AO Smith Water Heater 12 40GPC T 100 User Manual

SERVICE HANDBOOK FOR  
STANDARD RESIDENTIAL  
HIGH EFFICIENCY ATMOSPHERIC VENT  
(FVIR) GAS WATER HEATERS  
MODELS:  
GAHH 40 100,  
GAHH 50 100,  
GP 6 40YPC T 100,  
GP 6 50YPC T 100,  
PCG250T403NOV 100,  
PCG2J5040T3NOV 100,  
12 50GPC T 100,  
PCG6240T403NOV 100,  
PCG2J4040T3NOV 100,  
12 40GPC T 100,  
PCG2J4040T3NOV 100,  
PCG2J5040T3NOV 100  
Printed in U.S.A. 10/10  
318181-000  
ALL TECHNICAL AND WARRANTY QUESTIONS  
SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS PURCHASED.  
IF YOU ARE UNSUCCESSFUL, CONTACTA. O. SMITH WATER HEATERS RESIDENTIAL TECHNICALASSISTANCE  
AT 1-800-527-1953 OR WWW.HOTWATER.COM.  
2
SERVICE HANDBOOK  
Your safety and the safety of others is extremely important in the servicing of this water heater. Many  
safety-related messages and instructions have been provided in this handbook and on the water heater  
to warn you and others of a potential hazard. Read and obey all safety messages and instructions  
throughout this handbook. It is very important that the meaning of each safety message is understood  
by you and others who service this water heater.  
The information contained in this handbook is designed to answer commonly faced situations encoun-  
tered in the operation of the standard Residential Gas product line and is not meant to be all-inclusive.  
If you are experiencing a problem not covered in this handbook, please contact the Technical Informa-  
tion Center listed on the back of this handbook for further assistance. Additional information is also  
available on the web site listed on the back of this handbook. This handbook is intended for use by  
licensed plumbing professionals and reference should be made to the Installation Instructions and Use  
& Care Guide accompanying the product. This handbook contains supplemental information to the  
Installation Instructions and Use & Care Guide.  
When servicing residential water heaters, it is essential that you return the unit to a safe condition  
before you leave the site. All original components must be re-installed and all safety measures must be  
implemented. In addition, the recommended water temperature setting is 120° F.  
IMPORTANT: It is recommend that on every service call an inspection & cleaning of the air  
intake chamber screen and combustion chamber and air diverter assembly be performed. See  
page 24.  
Tools Required (for servicing gas models):  
• phillips head screw driver  
• 3/8, 7/16, & 3/4 inch open end wrenches  
• 3/16 inch Allen wrench  
• 1-1/16 inch – 6 point – socket – for anode removal  
• 5/16” nut driver  
• pliers  
• electrical multimeter (with alligator leads)  
• digital or analog manometer  
• gas pressure gauge  
Teflon® tape  
• hose – to drain tank  
Digital manometer shown.  
Teflon® is a registered trademark of E.I. Du Pont De Numours and Company.  
3
Breathing Hazard - Carbon Monoxide Gas  
Install vent system in accordance with  
codes.  
Do not operate water heater if flood  
damaged  
Fire or Explosion Harzard  
Do not store or use gasoline or other flammable vapors and  
liquids in the vicinity of this or any other appliance.  
Heater should not be installed for High  
Altitude operation above 10,100 feet  
(3,078 m).  
Avoid all ignition sources if you smell Natural or LP gas.  
Do not expose water heater control to excessive gas  
pressure.  
Do not operate if soot buildup.  
Use only gas shown on rating plate.  
Do not obstruct water heater air intake  
with insulating jacket.  
Maintain required clearances to combustibles.  
Keep ignition sources away from faucets after extended  
period of non-use.  
Do not place chemical vapor emitting  
products near water heater.  
Gas and carbon monoxide detectors  
are available.  
Read instruction manual before  
installing, using or servicing  
water heater.  
Breathing carbon monoxide can cause brain damage or death.  
Always read and understand instruction manual.  
Improper installation and use may result  
in property damage.  
Do not operate water heater if flood damaged.  
Install in location with drainage.  
Fill tank with water before operation.  
Be alert for thermal expansion.  
Refer to instruction manual for installation and service.  
4
TABLE OF CONTENTS  
INTRODUCTION:  
Service Handbook Introduction...........................................................................................................................3  
Warnings and Cautions.......................................................................................................................................4  
Table Of Contents ...............................................................................................................................................5  
INSTALLATION / OPERATION:  
Basic Installation & Operation.............................................................................................................................6  
Combustion Air and Vent System Requirements.......................................................................................... 7-10  
KNOW YOUR WATER HEATER:  
Know the Water Heater’s Component Parts................................................................................................11-13  
Water Heater Operation....................................................................................................................................14  
Filling and Draining the Water Heater...............................................................................................................15  
Lighting Instructions..........................................................................................................................................16  
ADJUSTING TEMPERATURE CONTROL:  
Adjusting the Temperature on the Electronic Control Display...........................................................................17  
Using the Electronic Control Display........................................................................................................... 18-19  
Electronic Control Display Troubleshooting ................................................................................................ 20-23  
COMPONENTS REMOVAL / REPLACING:  
External Inspection and Cleaning .....................................................................................................................24  
Electronic Control Display Removal / Replacement .........................................................................................25  
Powered Anode Removal / Replacement ................................................................................................... 26-27  
Pressure Switch Removal / Replacement.........................................................................................................28  
Transformer Removal / Replacement ......................................................................................................... 29-30  
Air Intake Chamber Box Removal / Replacement ...................................................................................... 31-33  
Wiring Harnesss Removal / Replacement .................................................................................................. 34-36  
Air Intake Chamber Fan Removal / Replacement ...................................................................................... 37-38  
Pressure Tubing Removal / Replacement .................................................................................................. 39-40  
Inner Door/Manifold/Burner Assembly Removal / Replacement................................................................. 41-42  
Flame Sense/Hot Surface Igniter Removal / Replacement ..............................................................................43  
Burner Removal / Replacement.................................................................................................................. 44-46  
Burner Orice Removal / Replacement ...................................................................................................... 47-49  
Gas Control Valve/Thermostat Removal / Replacement............................................................................. 50-52  
CHECKPOINTS / GENERAL INFORMATION:  
Checking the Gas Supply Pressure..................................................................................................................52  
Gas Water Heater Sizing Guide -and- Leakage Checkpoints.........................................................................53  
General Information .................................................................................................................................... 54-55  
5
BASIC INSTALLATION & OPERATION  
INSTALLATION OF RESIDENTIAL GAS WATER HEATER  
Water  
Supply- Cold*  
Water  
Shut-Off  
Valve  
See Labels and  
Exhaust Vent to  
Ouside of Building  
Installation Instructions  
and Use & Care Guide  
for clearances.  
*Massachusett: Install  
a vacuum relief in cold  
water line per section  
19 MGL 142.  
Union  
Use Draft Hood  
supplied with unit  
Union  
Expansion Tank  
Pressurize to Equal  
Supply Water Pressure*  
(Relieve water pressure  
on the expansion tank  
before adjusting air  
pressure.)  
To Fixtures - Hot  
Gas  
Tempered Water  
Supply  
To Fixtures  
Temperature-Pressure Relief Valve  
with discharge piped to an  
adequate drain. Do not cap or plug.  
Untempered  
Hot Water  
Cold  
Water  
Inlet  
Control  
Display  
Manual Gas Shut-off Valve  
Air Intake Chamber  
Hot  
Air is drawn in for combustion.  
Keep area clean and free from  
flammables and flammable vapors.  
Water  
Outlet  
Gas Control Valve/Thermostat  
Recommended setting of 120°F.**  
Mixing Valve  
(Set to 120°F)  
Do not cap or plug.  
Follow the Mixing Valve  
Manufacturer’s Instructions  
6” Maximum Air Gap  
NOTE: Local codes  
may vary.  
Union  
Sediment Trap  
Drain  
(Drip Leg) 3” Minimum.  
Electrical Plug  
Metal Drain Pan piped to an adequate drain.  
NOTE: Drain pan diameter must be at least  
2 inches wider than the diameter of the  
water heater.  
FV Sensor  
Bracket  
The water heater must be installed according to all local and state codes or in the absence of local  
and state codes, the “National Fuel Gas Code”’ ANSI Z223.1(NFPA 54)- current edition.  
*
NOTE: If on a well system the expansion tank should be set to the maximum pressure of the pump tank.  
** White-Rodgers® gas control valve/thermostat shown in this figure.  
Figure 1  
6
COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS  
Combustion Air Requirements:  
Table 1:  
BTUH Input  
Minimum Square  
Feet with  
Typical Room  
with 8’ Ceiling  
WARNING  
Carbon Monoxide Warning  
8’ Ceiling  
30,000  
45,000  
60,000  
75,000  
90,000  
105,000  
120,000  
135,000  
188  
281  
375  
469  
563  
657  
750  
844  
9 x 21  
14 x 20  
15 x 25  
15 x 31  
20 x 28  
20 x 33  
25 x 30  
28 x 30  
Water heater must be vented to outdoors.  
Vent must be installed by a qualified technician using  
the local and state codes or, in the absence of local  
and state codes, the National Fuel Gas Code,  
ANSI Z223.1 (NFPA 54) - current edition, and/or the  
installation instructions.  
Examples of a qualified technican include: gas  
technicians, authorized gas company personel, and  
authorized service persons.  
IMPORTANT:  
The area must be open and be able to provide  
the proper air requirements to the water  
heater. Areas that are being used for storage  
or contain large objects may not be suitable  
for water heater installation.  
Failure to so do can result in death or carbon monoxide  
poisoning.  
IMPORTANT: Air for combustion and ventilation  
must not come from a ammable or corrosive at-  
mosphere. Any failure due to ammable or corro-  
sive elements in the atmosphere is excluded from  
warranty coverage.  
Water heaters installed in open spaces in  
buildings with unusually tight construction may  
still require outdoor air to function properly. In  
this situation, outside air openings should be  
sized the same as for a confined space.  
Modern home construction usually requires  
supplying outside air into the water heater  
area.  
The following types of installation (not limited to  
the following) will require outdoor air for combus-  
tion due to chemical exposure and may reduce  
but not eliminate the presence of corrosive chemi-  
cals in the air:  
Room exhaust fans may effect air  
requirements.  
beauty shops  
Conned Space: For the correct and proper  
operation of this water heater, ample air must be  
supplied for the combustion, ventilation, and dilu-  
tion of ue gases. Small enclosures and conned  
areas must have two permanent openings so that  
sufcient fresh air can be drawn from outside of  
the enclosure. One opening shall be within 12  
inches of the top and one within 12 inches of the  
bottom of the enclosure.  
The size of each opening (free area) is deter-  
mined by the total BTUH input of all gas utilization  
equipment (i.e., water heaters, furnaces, clothes  
dryers, etc.) and the method by which the air is  
provided. The BTUH input can be found on the  
water heater rating plate. Additional air can be  
provided by two methods:  
photo processing labs  
buildings with indoor pools  
water heaters installed in laundry, hobby, or  
craft rooms  
water heaters installed near chemical storage  
areas  
water softeners  
Combustion air must be free of acid-forming  
chemicals such as sulfur, uorine, and chlorine.  
These elements are found in aerosol sprays, de-  
tergents, bleaches, cleaning solvents, air freshen-  
ers, paint, and varnish removers, refrigerants, and  
many other commercial and household products.  
When burned, vapors from these products form  
highly corrosive acid compounds. These prod-  
ucts should not be stored or used near the water  
heater, air inlet, or air intake path.  
1. All air from inside the building.  
2. All air from outdoors.  
Combustion and ventilation air requirements are  
determined by the location of the water heater.  
The water heater may be located in either an  
open (unconned) area or in a conned area or  
small enclosure such as a closet or small room.  
Conned spaces are areas with less than 50 cubic  
feet for each 1,000 BTUH of the total input for all  
gas-using appliances.  
Unconned Space: A water heater in an uncon-  
ned space uses indoor air for combustion and  
requires at least 50 cubic feet for each 1,000  
BTUH of the total input for all gas appliances. The  
table below shows a few examples of the mini-  
mum square footage (area) required for various  
BTUH inputs.  
12” MAXIMUM  
CLOSET  
OR  
OTHER  
CONFINED  
SPACE  
PERMANENT  
OPENINGS TO  
THE OUTSIDE OR  
ADDITIONAL  
ROOMS WITHIN  
THE BUILDING  
12” MAXIMUM  
Figure 2.  
7
COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS  
All Air from Inside the Building: When  
Minimum Free Area of Permanent Openings for  
Ventilation and Combustion Air Supply - All Air from  
Outdoors Only.  
additional air is to be provided to the conned  
area from additional room(s) within the building,  
the total volume of the room(s) must be of  
sufcient size to properly provide the necessary  
amount of fresh air to the water heater and other  
gas utilization equipment in the area. Each of the  
two openings shall have a minimum free area  
of 1 square inch per 1,000 BTUH of the total  
input rating of all gas utilization equipment in  
the conned area, but not less than 100 square  
inches for each opening.  
Based on total BTUH input rating for all utilizing  
equipment within the conned space.  
Minimum Free Area  
Per Opening (sq. in.)  
Reference  
Drawing  
Opening Source  
*Direct to outdoors 1 sq. in, per 4000 BTUH  
Figure 4  
Figure 5  
Figure 6  
Figure 7  
Vertical Ducts  
Horizontal Ducts  
Single Opening  
1 sq. in, per 4000 BTUH  
1 sq. in, per 2000 BTUH  
1 sq. in, per 3000 BTUH  
Example: A water heater with an input rating of 50,000 BTUH  
using horizontal ducts would require each opening to have a  
minimum free area of 25 square inches.  
CONFINED  
SPACE  
Minimum free area = 50,000 BTUH x 1 sq. in. / 2000 BTUH = 25  
sq. in.  
These openings connect directly with the outdoors  
through a ventilated attic, a ventilated crawl space, or  
through an outside wall.  
*
PERMANENT  
OPENINGS  
Consult the local codes of your area for specific  
ventilation and combustion air requirements  
1 SQUARE  
INCH/1000  
BTUH  
(MINIMUM  
100 SQ. IN.  
FOR EACH  
OPENING)  
ABLE VENT  
TO OUTDOORS  
INSTALL ABOVE  
INSULATION  
Figure 3.  
CONFINED  
OUTLET  
All Air from Outdoors: Outdoor fresh air can be  
provided to a confined area either directly or by  
the use of vertical and horizontal ducts. The fresh  
air can be taken from the outdoors or from crawl  
or attic spaces that freely communicate with the  
outdoors. Attic or crawl spaces cannot be closed  
and must be properly ventilated to the outside.  
Ductwork must be of the same cross-sectional  
area as the free area of the opening to which  
they connect. The minimum dimension of  
rectangular air ducts cannot be less than three  
inches. The size of each of the two openings is  
determined by the method in which the air is to  
be provided. Refer to the table below to calculate  
the minimum free area for each opening.  
SPACE  
AIR TO  
ATTIC 1 SQ.  
INCH PER  
4000 BTUH  
INLET AIR FROM  
THE CRAWL SPACE  
ALTERNATE  
AIR INLET  
1 SQ. INCH PER  
4000 BTUH  
100 SQ. INCH MINIMUM (EACH)  
OPEN  
FOUNDATION  
VENT  
ALL AIR FROM OUTDOORS: INLET AIR FROM VENTILATED  
CRAWL SPACE/OUTLET AIR TO VENTILATED ATTIC  
Figure 4.  
GABLE VENT  
TO OUTDOORS  
Louvers and Grilles: In calculating free  
area for ventilation and combustion air supply  
openings, consideration must be given to the  
blocking effect of protection louvers, grilles, and  
screens. These devices can reduce airflow, which  
in turn may require larger openings to achieve the  
required minimum free area. Screens must not be  
smaller than 1/4” mesh. If the free area through  
a particular design of louver or grille is known, it  
should be used in calculating the specified free  
area of the opening. If the design and free area  
are not known, it can be assumed that most wood  
louvers will allow 20 - 25% of free area while  
metal louvers and grilles will allow 60 - 75% of  
free area. Louvers and grilles must be locked  
open or interconnected with the equipment so that  
they are opened automatically during equipment  
operation. Keep louvers and grilles clean and free  
of debris or other obstructions.  
INSTALL ABOVE  
INSULATION  
OUTLET AIR TO  
CONFINED  
ATTIC 1 SQ. INCH  
SPACE  
PER 4000 BTUH -  
100 SQ. INCH MIN.  
(EACH)  
INLET AIR DUCT  
1 SQ. INCH PER  
4000 BTUH - 100  
SQ. INCH MIN.  
(EACH)  
12” MAXIMUM  
ALL AIR FROM OUTDOORS THROUGH VENTILATED ATTIC  
Figure 5.  
8
COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS  
Vent Connectors:  
1. Type B, Double wall, U.L. Listed Vent Pipe.  
2. Single wall Vent Pipe.  
1 SQ. INCH PER  
2000 BTUH  
100 SQ. INCH  
MINIMUM (EACH)  
Maintain the manufacturer’s specied minimum  
clearance from combustible materials when using  
type B double wall vent pipe.  
CONFINED  
SPACE  
OUTLET  
Vent connectors made of type B, double wall  
vent pipe material may pass through walls or  
partitions constructed of combustible material if  
the minimum listed clearance is maintained.  
Maintain a one inch minimum clearance from all  
combustible materials when using single wall vent  
pipe.  
OUTDOOR  
AIR DUCTS  
INLET  
1 SQ. INCH PER  
2000 BTUH 100 SQ. INCH  
MINIMUM (EACH)  
IMPORTANT: Single wall vent pipe cannot be  
used for water heaters located in attics and may  
not pass through attic spaces, crawl spaces or  
any conned or inaccessible location. A single wall  
metal vent connector cannot pass through any  
interior wall.  
ALL AIR FROM OUTDOORS USING HORIZONTAL DUCTS  
Figure 6.  
ALTERNATIVE  
OPENING  
LOCATION  
When installing a vent connector, please note the  
following  
Install the vent connector avoiding  
unnecessary bends, which create resistance  
to the flow of vent gases.  
1 SQ. INCH  
PER 3000 BTUH  
100 SQ. INCH  
MINIMUM (EACH)  
CONFINED  
SPACE  
Install without dips or sags with an upward  
slope of at least 1/4-inch per foot.  
Joints must be fastened by sheet metal  
screws or other approved means. It must be  
supported to maintain clearances and prevent  
separation of joints and damage.  
ALL AIR FROM OUTDOORS - USING A SINGLE PERMANENT OPENING  
The length of the vent connector cannot  
exceed 75% of the vertical vent height.  
The vent connector must be accessible for  
cleaning, inspection, and replacement.  
Vent connectors cannot pass through any  
ceiling, floor, firewall, or fire partition.  
It is recommended (but not mandatory) that  
a minimum 12 inches of vertical vent pipe be  
installed on the draft hood prior to any elbow  
in the vent system.  
Figure 7.  
Vent Pipe System: This water heater must be  
properly vented for the removal of exhaust gases  
to the outside atmosphere. Correct installation of  
the vent pipe system is mandatory for the proper  
and efcient operation of this water heater and is  
an important factor in the life of the unit.  
The vent pipe must be installed according to all  
local and state codes or, in the absence of local  
and state codes, the “National Fuel Gas Code”,  
ANSI Z223.1(NFPA 54)-current edition. The vent  
pipe installation must not be obstructed so as  
to prevent the removal of exhaust gases to the  
outside atmosphere.  
IMPORTANT: Existing vent systems must be  
inspected for obstructions, corrosion, and proper  
installation.  
Chimney Connection: IMPORTANT: Before  
connecting a gas vent to a chimney, make sure  
the chimney passageway is clear and free of  
obstructions. The chimney must be cleaned if  
previously used for venting solid fuel appliances  
or fireplaces. Also consult local and state codes  
for proper chimney sizing and application or, in the  
absence of local and state codes, the “National Fuel  
Gas Code”, ANSI Z223.1(NFPA 54)-current edition.  
U.L. recognized fuel gas and carbon monoxide  
(CO) detectors are recommended in all  
applications and should be installed using the  
manufacturer’s instructions and local codes, rules,  
or regulations.  
The connector must be installed above the  
extreme bottom of the chimney to prevent  
potentially blocking the flue gases.  
Vent Pipe Size: It is important that you follow the  
guidelines in these instructions for sizing a vent  
pipe system. If a transition to a larger vent size is  
required, the vent transition connection must be  
made at the draft hood outlet. DO NOT reduce  
the vent size to less than the draft hood outlet  
diameter.  
9
COMBUSTION AIR AND VENT SYSTEM REQUIREMENTS  
The following gures are examples of vent pipe  
system installations and may or may not be typical  
for your specic application. Consult the “National  
Fuel Gas Code”, NFPA 54, ANSI Z223.1-current  
edition and the guidelines set forth by prevailing  
local codes.  
The connector must be firmly attached and  
sealed to prevent it from falling out.  
To aid in removing the connector, a thimble or  
slip joint may be used.  
The connector must not extend beyond the  
inner edge of the chimney as it may restrict  
the space between it and the opposite wall of  
the chimney  
2 FT. Minimum Above  
Any Object Within  
10 FT. Horizontally  
3 FT.  
Minimum  
2 FT. Minimum Above Any Object  
Support Strap  
3 FT.  
Within 10 FT. Horizontally  
Minimum  
Type B Double  
Wall Vent Pipe  
Maintain  
Clearance*  
Support Strap  
Seal  
Maintain  
Clearance*  
**Maintain  
Specified  
Clearance  
Do Not Extend  
Vent Beyond Edge  
Of Chimney  
Vent  
Connector  
Slope Up  
1/4 Inch  
Vent  
Connector  
Per Foot  
Minimum  
Slope Up  
1/4 Inch  
Per Foot  
Minimum  
Venting Gas Vent System With Type B Double Wall Vent Pipe.  
Figure 9.  
Chimney Termination Vent System  
Consult the table found in the “National Fuel Gas  
Code”, NFPA 54, ANSI Z223.1-current edition to  
determine the minimum height from roof to lowest  
discharge opening.  
Figure 8.  
Do not reduce the vent to less than the draft  
hood outlet diameter. Do not terminate the vent  
connector in a chimney that has not been certified  
for this purpose. Some local codes may prohibit  
the termination of vent connectors in a masonry  
chimney.  
Listed Vent Cap  
Maintain Manufacturer’s  
Specified Minimum Clearance  
Vertical Exhaust Gas Vent: Vertical exhaust  
gas vents must be installed with U.L. listed type  
B vent pipe according to the vent manufacturer’s  
instructions and the terms of its listing.  
**Maintain  
Specified  
Support Strap  
Clearance  
Seal  
Maintain  
Clearance*  
It must be connected to the water heater’s draft  
hood by a listed vent connector or by directly  
originating at the draft hood opening.  
Vertical gas vents must terminate with a listed cap  
or other roof assembly and be installed according to  
their manufacturer’s instructions.  
Vent Connector  
Vent  
Connector  
Slope Up  
Unused Chimney  
1/4 Inch  
Flue Or Masonry  
Per Foot  
Enclosure  
Minimum  
Gas vents must be supported to prevent damage,  
joint separation, and maintain clearances to  
combustible materials.  
Venting Through Chimney With Type B Double Wall Vent Pipe.  
IMPORTANT: This gas vent must be terminated in a  
vertical position to facilitate the removal of the burnt  
gases.  
Figure 10.  
An unused chimney ue or masonry enclosure  
may be used as a passageway for the installation  
of a gas vent. NOTE: The chimney ue or masonry  
enclosure size may be too large to allow proper  
venting.  
Common (combined) venting is allowable with  
vertical type B vent systems and lined masonry  
chimneys as long as proper draft for the water  
heater is established under all conditions of  
operation. CAUTION: DO NOT common vent this  
water heater with any power vented appliance.  
Maintain vent pipe clearance requirements to local,  
*
state and/or the “National Fuel Gas Code”, ANSI  
Z223.1(NFPA 54)-current edition.  
NFPA 211, Standard for Chimneys, Fireplaces,  
**  
Vents, and Solid Fuel-Burning Appliances states  
that these chimneys are intended to be installed  
in accordance with the installation instructions  
provided with each chimney support assembly.  
Minimum air space clearance to combustible  
materials should be maintained as marked on the  
chimney sections.  
10  
KNOW THE WATER HEATER’S COMPONENT PARTS  
Electronic Control Display (Upper Control)  
The Electronic Control Display panel used on this water heater provides an easy-to-read, eye level display  
for temperature adjustment, fault code diagnostics and recall, powered anode rod operation and setting the  
temperature scale for either Fahrenheit (°F) or Celsius (°C).  
Figure 11.  
Electronic Control Display  
(Upper Control)  
Gas Control Valve/Thermostat (Lower Control)  
The gas control valve/thermostat is where the incoming gas supply is connected to the water heater. It is  
used in conjunction with the electronic control display to start or stop main burner operation. There is an  
On/Off switch located on the right-hand side of the control. The gas control valve/thermostat is energized  
by a 24 VAC power supply transformer and uses a temperature sensing probe to open or close the flow  
of gas to the main burner. The gas control valve has an inlet filter built into its body to prevent impurities in  
the gas system from contaminating the internal valves and a LED diagnostic light located in the lower right  
hand corner of the valve to display any micro-computer fault experienced by the control. On the bottom of  
the control is where electrical connections to the other component parts are attached along with the gas  
supply (manifold tube) to the main burner. The gas control/valve thermostat of this water heater is suitable  
for use on Natural gas only.  
Figure 12.  
Gas Control Valve/ Thermostat  
On/Off Switch  
located on  
the right side.  
Bottom View  
Gas Supply- Inlet  
Temperature Probe  
/High Limit Probe  
1
8 Pin Systems  
Connector  
2
5 Pin Communications  
Connector  
Manifold Tube  
3
3 Pin Ignitor  
Connector  
Pressure  
Switch / Fan,  
FV Sensor  
Connector  
Power Supply  
Transformer  
Connector  
4
4
2 Pin Power  
Connector  
1
3
Igniter/Flame  
Sense  
Connector  
2
Control Display,  
Anode Rod  
Connector  
11  
KNOW THE WATER HEATER’S COMPONENT PARTS  
Burner/Manifold Door Assembly  
The burner/manifold door assembly consists of several components such as: main burner, burner orifice,  
manifold tube and flame sense / hot surface igniter. See figure below for the complete list of components  
(Figure 13).  
Figure 13.  
Main Burner  
Manifold  
Tube  
Manifold  
Door  
Scoop side to be placed  
on the same side as  
View Port.  
View  
Port  
Flame Sense / Hot Surface  
Igniter Assembly  
Burner Orifice*  
Flame Sense/  
Hot Surface  
Igniter Assembly  
Burner Screws  
Door Gasket  
*DO NOT operate the water heater without the burner orifices installed.  
Figure 14.  
Air Intake Chamber Fan  
The small fan at the top of the air intake chamber  
on the side of the water heater is used to draw in  
necessary combustion air for the efficient operation  
of the main burner. The fan pressurizes the sealed  
combustion chamber which in turn allows the flue  
baffle inside the center flue tube to slow down the  
hot exhaust gases so heat can be extracted into the  
water before exiting into the vent system. The air  
intake chamber fan runs for about 5 seconds to pre-  
purge the combustion chamber before the beginning  
of an ignition sequence when there is a call for  
heat. The fan will continue to operate while the main  
burner is in operation and for about 5 seconds after  
the temperature set point has been achieved. The  
air intake chamber screen covering the fan should  
be inspected and cleaned periodically to assure it is  
not limiting air flow into the chamber (Figure 14).  
Air intake  
Chamber  
Screen  
Air intake  
Chamber  
Fan  
Air intake  
Chamber  
Figure 15  
Pressure Switch  
A pressure switch in the control string of this water  
heater is used to verify there is an adequate flow of  
combustion air into the combustion chamber before  
and during main burner operation. It is electrically  
connected to the gas control valve/thermostat and  
controls the opening and closing of the gas valve.  
If there is an insufficient air supply being delivered  
to the combustion chamber the pressure switch will  
not allow the water heater to operate (Figure 15).  
Pressure  
Switch  
12  
KNOW THE WATER HEATER’S COMPONENT PARTS  
Figure 16.  
Flammable Vapor Cut Off Switch (FV Sensor)  
The water heater is equipped with a FV sensor, for  
detecting the presence of flammable vapors (e.g.  
spilled gasoline). When the sensor detects those  
vapors, the heater will shut down and not operate.  
If flammable vapors are detected or the sensor  
is inoperative, an icon will flash on the electronic  
control display and the heater will go into a lockout  
mode. The water heater will not function again until  
the flammable vapors have been eliminated and the  
control is manually reset using a special Flammable  
Vapor sensor reset sequence. (Figure 16).  
FV Sensor  
Figure 17.  
Power Anode Rod  
To protect the glass-lined water tank from corrosion  
through electrolysis, this water heater is equipped  
with a non sacrificial powered anode rod. Unlike  
conventional magnesium or aluminum anode rods  
used in water heaters, the powered anode does  
not deteriorate and is less likely to contribute to  
the occurrence of “Smelly (Rotten Egg) Water”  
(Figure 17).  
Powered  
Anode  
Rod  
HOW THE WATER HEATER’S COMPONENT PARTS ARE CONNECTED  
Figure 18.  
Gas Control  
Air Intake  
Chamber Fan  
Valve / Thermostat  
Anode  
Rod  
Pressure  
Switch  
Control Display  
CAUTION:  
DO NOT USE AN EXTENSION  
CORD TO CONNECT THE  
TRANSFORMER TO AN  
ELECTRICAL OUTLET.  
Igniter/Flame  
Sense Connector  
FV  
Sensor  
CAUTION:  
Power Supply  
Transformer  
LABEL ALL WIRES PRIOR TO  
DISCONNECTION WHEN SERVICING  
CONTROLS. WIRING ERRORS CAN CAUSE  
IMPROPER AND DANGEROUS OPERATION.  
VERIFY PROPER OPERATION AFTER SERVICING.  
13  
WATER HEATER OPERATION  
The figure below shows the water heater’s sequence of operation when a call for heat is initiated. The gas  
control valve/thermostat will attempt to light the burner three times. If the flame sense rod in the burner/  
manifold assembly does not detect ignition, the control will enter lockout mode indicated by the electronic  
control display’s flashing of the appropriate status code.  
SEQUENCE OF OPERATION  
Call for heat indicated by  
flashing of display screen  
status codes.  
Gas valve/thermostat will open  
for 4 second trial for ignition  
and fan will turn on.  
Gas valve/thermostat will do a  
relay check (relay clicks will be  
heard).  
Main burner flame is detected by  
flame sense rod. Air intake fan  
and main burner will continue to  
operate until water temperature  
inside the tank reaches  
temperature set point.  
Display will show temperature  
set point during call for heat.  
Gas valve/thermostat is de-  
energized and air intake fan  
continues for a post purge time  
of approximately 5 seconds.  
Draft Blower is energized.  
System will verify pressure  
switch operation and start a  
5 second pre-purge, then air  
intake fan will turn off.  
Water heater returns to standby  
mode.  
Ignitor will start a 12 second  
warm up period. “IGN” will  
show on display.  
14  
FILLING, DRAINING AND FLUSHING THE WATER HEATER TANK  
It is recommended that the tank be drained and flushed every 6 months to remove sediment which  
may build up during operation. The water heater should be drained if being shut down during freezing  
temperatures. To drain the tank, perform the following steps:  
1. Turn off the gas to the water heater at the manual gas shut-off valve and turn off the electrical power to  
the gas control/thermostat valve.  
2. Open a nearby hot water faucet until the water is no longer hot.  
3. Close the cold water inlet valve.  
4. Remove the outer door and connect a hose to the drain valve and terminate it to an adequate drain or  
external to the building (Figure 19).  
5. Open the water heater drain valve and allow all the water to drain from the tank. Flush the tank with  
water as needed to remove sediment.  
6. Close the drain valve, refill the tank, and restart the heater as directed in the lighting instructions on the  
front of the heater.  
IMPORTANT: Condensation may occur when refilling the tank and should not be confused with a tank leak.  
NOTE: If the water heater is going to be shut down for an extended period,  
the drain valve should be left open.  
Figure 19.  
Hose  
Outer Door  
Adequate Drain  
15  
LIGHTING INSTRUCTIONS  
Read and understand these directions thoroughly before attempting to operate the water heater. Make sure  
the view port is not missing or damaged. Make sure the tank is completely filled with water before operating  
the water heater. The gas control valve/thermostat has an “On/Off Switch” and needs to be turned on  
before the water heater is operational. Check the label on the front of the water heater near the gas control  
valve/thermostat for the correct gas. Do not start this water heater with any gas other than the one listed on  
the label. If you have any questions or doubts, consult the gas supplier or gas utility company. The following  
Lighting Instruction label appears on the front of the water heater.  
FOR YOUR SAFETY READ BEFORE OPERATING  
WARNING: If you do not follow these instructions exactly, a fire or  
explosion may result causing property damage, personal injury  
or loss of life.  
FLAMMABLE  
BEFORE OPERATING: ENTIRE SYSTEM MUST BE FILLED WITH WATER AND AIR PURGED FROM ALL LINES.  
This appliance does not have a pilot. It is equipped with  
an ignition device that will automatically light the  
burner. Do not try to light the burner by hand.  
BEFORE OPERATING smell all around the appliance  
area for gas. Be sure to smell next to the floor because  
some gas is heavier than air and will settle on the floor.  
A.  
If you cannot reach your gas supplier, call the  
fire department.  
Use only your hand to push in the electronic display  
buttons and gas control switch. Never use tools.  
If the control buttons will not push in, don't try to  
repair them, call a qualified service technician. Force  
or attempted repair may result in a fire or explosion.  
C.  
D.  
B.  
WHAT TO DO IF YOU SMELL GAS:  
Do not try to light any appliance.  
Do not use this appliance if any part has been  
under water. Immediately contact a qualified  
installer or service agency to replace a flooded  
water heater. Do not attempt to repair the unit.  
It must be replaced!  
Do not touch any electric switch;  
do not use any phone in your building.  
Immediately call your gas supplier from a neighbor’s  
phone. Follow the gas supplier’s instructions.  
OPERATING INSTRUCTIONS  
ON  
OFF  
ON/OFF  
SWITCH  
"GAS CONTROL"  
"ELECTRONIC DISPLAY"  
1.  
STOP! Read the safety information  
above on the label.  
8. Set the ON/OFF switch on the gas control to the  
"ON" postition.  
2.  
3.  
Turn on all electrical power to the appliance.  
Set the ON/OFF switch on the gas control to the  
"ON" position.  
Set the Electronic Display to the desired setting by first  
9.  
Set the Electronic Display to the lowest  
4.  
pressing the COOLER  
and HOTTER  
but-  
setting by first pressing the COOLER  
and  
HOTTER  
buttons together and holding for 1  
tons together and holding for 1 second. Then press  
second. Then press the COOLER  
the lowest setting.  
button to  
the HOTTER  
is reached.  
button until the desired setting  
5.  
6.  
Set the ON/OFF switch on the gas control to the  
"OFF" position.  
This appliance is equipped with a device  
which automatically lights the burner.  
DANGER: Hotter water increases the  
risk of scald injury. Consult the instruction  
manual before changing temperature.  
If the appliance will not operate, follow the instruc-  
tions "TO TURN OFF GAS TO APPLIANCE" and  
call your technician or gas supplier.  
10.  
DO NOT TRY TO LIGHT THE BURNER BY HAND.  
Wait five (5) minutes to  
If you then smell gas,  
clear out any gas.  
STOP! Follow "B" in  
7.  
WARNING: TURN OFF ALL  
the safety information above on this label. If you  
don't smell gas, go to the next step.  
ELECTRIC POWER BEFORE SERVICING.  
TO TURN OFF GAS TO APPLIANCE  
Set the Electronic Display to the lowest setting by first  
1.  
2. Set the ON/OFF switch on the gas control to the  
"OFF" postition.  
pressing the COOLER  
tons together and holding for 1 second. Then press  
the COOLER button to the lowest setting.  
and HOTTER  
but-  
3.  
Turn off all electrical power to the appliance if  
service is to be performed.  
Figure 20.  
16  
ADJUSTING THE TEMPERATURE ON THE  
ELECTRONIC CONTROL DISPLAY  
Adjusting the Temperature Set Point - The thermostat of this water heater has been factory set at its  
lowest position. It is adjustable and must be reset to the desired temperature setting to reduce the risk of  
scald injury. The electronic control display temperature should be set at approximately 120°F (49°C) and  
this is the preferred starting point, see Figure 21 Some states have a requirement for a lower setting. If you  
need hotter water, follow directions for temperature adjustment, but beware of the warnings in this section.  
Pressing the “COOLER” button decreases temperature and pressing the “HOTTER” button increases  
the temperature.  
To avoid any unintentional changes in water temperature settings, the control has a tamper resistant  
feature for changing the temperature setting. To change the temperature setting follow these instructions:  
1. “Unlock” the temperature indicators by holding down both “COOLER” and “HOTTER” temperature  
adjustment buttons at the same time for one second (See Figure 21). The temperature indicators will light  
up and will only remain on for 30 seconds if no further buttons are pressed. After 30 seconds the control  
will go back to “Lock” mode (“Lock” mode indicates a temperature setting is locked into the control  
memory).  
2. Release both of the temperature adjustment buttons.  
A. To decrease the temperature press and release the “COOLER”  
button until the desired setting is reached.  
B. To increase the temperature press and release the “HOTTER”  
button until the desired setting is reached.  
NOTE: Should overheating occur or the gas supply fail to shut off, turn off the manual gas control valve to  
the heater.  
Figure 21.  
Gas Control Valve/Thermostat Settings  
HOTTER  
COOLER  
Electronic Control Display  
Water  
Temperature  
°F  
Time for 1st  
Degree Burn  
(Less Severe Burns)  
Time for Permanent Burns  
2nd & 3rd Degree  
(Most Severe Burns)  
110  
116  
116  
122  
131  
140  
149  
154  
(normal shower temp.)  
(pain threshold)  
35 minutes  
45 minutes  
5 minutes  
25 seconds  
5 seconds  
2 seconds  
1 second  
1 minute  
5 seconds  
2 seconds  
1 second  
instantaneous  
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15,1978)  
Table 2  
17  
USING THE ELECTRONIC CONTROL DISPLAY  
How to select or change the temperature scale from Fahrenheit (°F) to Celsius (°C).  
Gas Control Valve/Thermostat Settings  
Figure 22.  
HOTTER  
COOLER  
Electronic Control Display  
1. The temperature scale defaults to Fahrenheit (°F).  
2. To change to Celsius (°C), press the two temperature adjustment buttons at the same time for more  
than five (5) seconds but less than 10 seconds to enter the Temperature Scale Selection mode. In this  
mode the currently active temperature scale indicator (°F or °C) will start to flash. When in this mode a  
button press of either the red up arrow, or the blue down arrow button will cause the control to toggle  
the temperature scale between °F and °C (Figure 22).  
3. Once the selection has been made the user may exit this mode by again pressing the two temperature  
adjustment buttons at the same time for more than two (2) seconds but less than five (5) seconds. The  
control will also time out five (5) seconds after the last button press and return to the normal operational  
mode.  
Fault Code Diagnostics:  
• The control system of this water heater monitors inputs and outputs.  
• When the system determines a fault condition is present it will show the  
fault on the display.  
• Depending on the fault, the system may continue to operate or enter a  
timed lockout.  
• Lockout time varies depending on the fault.  
• When the lockout time expires, if the fault has been corrected, the system  
will attempt normal operation.  
Fault Code Retrieval:  
• The system will display the last eight (8) fault codes.  
• The system will display how many days ago each fault occurred, up to 14 days.  
Note: A “14” indicates that the fault occurred 14 or more days ago. Interrupting  
the power restarts the date code at “00”.  
• User must enter Field Service Mode to view information.  
• Current water temperature, measured at gas valve/thermostat will also be  
displayed in Field Service mode.  
Entering Field Service Mode:  
1. Press and hold both temperature adjust buttons (Figure 22).  
2. Hold both buttons as control passes from the set point display to Temperature Scale Selection menu.  
Continue to hold buttons until “CHECK” icon is displayed, then release buttons. This will take 10 to 15  
seconds.  
3. The display will show the current water temperature, “POWER” icon, “CHECK” icon and will flash any  
current fault icons. The backlight will always be displayed while in the Field Service Mode.  
18  
USING THE ELECTRONIC CONTROL DISPLAY  
Reviewing Fault Codes:  
1. Press the red up arrow button one time.  
2. The display will show either E0 or E1.  
3. If E0 is shown, there are no faults. By pressing the up arrow button again the display will exit the Field  
Service mode, or the control will exit automatically after no button is pressed for five (5) seconds.  
4. If E1 is shown, the control will flash the icons of the most recent fault.  
5. Pressing the red up arrow button again will shown how many days ago the fault occurred and continue to  
flash the corresponding fault icons.  
6. Interpreting the day of the fault occurrence is as follows...00 would be today, 01 would be yesterday, up to  
14 which would be 14 or more days ago.  
7. Continuing to press the up arrow button will scroll through all of the eight (8) most recent faults, if they exist,  
and its days ago of occurrence.  
8. After the last fault is reached the display will return to the first fault (E1) to allow for the faults to be reviewed  
again.  
Exiting Field Service Mode:  
• There are three (3) methods to exit the Field Service Mode, Manual, Manual and Clear, and Timed Exit.  
1. Manual exit is accomplished by pressing both the red up arrow and the blue down arrow buttons for  
one (1) second, but less than five (5) seconds while in the Field Service Mode, or by pressing the red  
up arrow button one (1) time after the “E0” is displayed during fault review while in the Field Service  
Mode. These methods will return the control to the standard operating mode and retain any fault codes  
stored in memory.  
2. Manual exit and fault clear is accomplished by pressing the red up arrow and the blue down arrow  
buttons for five (5) seconds while in the Field Service Mode. This method will return the control to the  
standard operating mode and at the end of the five (5) seconds clear all faults stored in memory  
and initiate a software reset indicated by all the LCD segments coming on for five (5) seconds. The  
temperature setting and scale, etc. will not be altered using this method of exit.  
3. Timed exit will occur while in the Field Service Mode if the control detects no button presses for a  
period exceeding five (5) minutes. The control will automatically return to the normal operating mode  
and keep all fault data retained in memory.  
FV-Sense Reset Sequence:  
Figure 23.  
Flammable liquids (such as gasoline, solvents, adhesives, LP gases,  
etc.) and other substances emit flammable vapors which can be  
ignited by a gas water heater’s hot surface igniter or main burner. The  
resulting flashback and fire can cause serious burns to anyone in the  
area. This water heater is equipped with a FV sensor for detecting the  
presence of flammable vapors. When the sensor detects those vapors,  
the unit will shut down and not operate. Even though this water heater  
is a flammable vapors ignition resistant water heater and designed to  
reduce the chances of flammable vapors being ignited, gasoline and  
other flammable substances should never be stored or used in the  
same vicinity or area containing a gas water heater or other open flame  
or spark producing appliance.  
FV Sensor  
Should the FV-Sensor of this water heater detect the presence of flammable vapors the following FV-Sense  
Reset Sequence must be entered into the Electronic Control Display. NOTE: BEFORE RESETTING THE  
FVIR SENSE IN THE ELECTRONIC CONTROL DISPLAY, THOROUGHLY INSPECT THE AREA AND REMOVE  
THE SOURCE OF THE FLAMMABLE VAPORS”.  
1. Manual reset is accomplished by first turning off the power to the water heater for at least 10 seconds.  
2. Then, while pressing the two temperature adjustment buttons on the display, turn the switch on the gas  
control valve/thermostat to the on position. All the display icons will start to flash. Temporarily release  
both temperature adjust buttons and within 2 seconds, press both temperatures adjust buttons again  
until all the display icons are on steady. Release the two temperature adjust buttons. The system will  
clear the fault, perform a reset, and normal operation will be restored.  
19  
ELECTRONIC CONTROL DISPLAY TROUBLESHOOTING  
ELECTRONIC CONTROL DISPLAY  
Please check guidelines below. For your safety, water heater service should be performed only by a qualified service person.  
Read the GENERAL SAFETY INFORMATION supplied by the water heater manufacturer.  
CONTROL DISPLAY STATUS  
“POWER” Flashing  
PROBLEM  
SOLUTION  
1. Check the 5-conductor data cable that  
runs between the upper and lower  
controls. Check that the wiring is not  
broken, and the connectors on both ends  
are properly seated in the mating  
connectors.  
1.  
Communication Error  
The system has detected a  
communication error between the  
upper and lower controls.  
2. Replace the upper control, if the error code  
does not clear - cycle power to the water  
heater “Off” and “On” to reset.  
3. Replace the lower control if the problem persists.  
1. Turn the power off for 10 to 20 seconds  
then on again to clear the error code.  
2.  
3.  
“HEATING” and “SHORT” Flashing  
“HEATING” and “OPEN” Flashing  
The self-diagnostic tests have  
found a problem with an internal  
circuit.  
2. If the error code persists or cannot be  
cleared, replace the lower control.  
1. Gas supply is turned off – pressure too  
low. Ensure supply and manifold gas  
pressures are within requirements in the  
installation manual. Manifold gas  
pressure is non-adjustable, if pressure is  
off by more than 0.3” W.C. (75 Pa)  
replace the lower control.  
Ignition/flame failure.  
The water heater has reached the  
maximum number of retries and is  
currently locked out for one hour.  
Cycle the power to the water  
heater off and on to reset.  
2. Low supply voltage – should be 115 –  
125 VAC.  
3. Ensure flame sensor is making good  
contact with the burner flame, ensure  
flame is steady.  
4. Ensure the flame sensor is clean – use  
TM  
ultra fine steel wool or Scotch-Brite pad  
to clean the flame sensor.  
5. Ensure the hot surface ignitor is  
positioned to provide consistent ignition.  
6. Check for any cracks in the ignitor  
assembly ceramic insulators – replace  
ignitor assembly if damaged.  
7. Check resistance of the ignitor at room  
temperature (77°F – 25°C) at the plug  
end. Replace ignitor if the resistance is  
not within 1.72 to 2.4 ohms at room  
temperature.  
1. Ensure flame sensor is making good  
contact with the burner flame, ensure  
flame is steady.  
4.  
5.  
“HEATING”, “OPEN”, and “SHORT” Flashing  
“ECO” and “OPEN” Flashing  
Weak flame sensor current.  
2. Ensure the flame sensor is clean – use  
TM  
ultra fine steel wool or Scotch-Brite pad  
to clean the flame sensor.  
1. Turn the power off for 10 – 20 seconds  
Water temperature in the tank has  
exceeded 185°F (85°C) and has  
activated the ECO.  
then on again to clear this error code.  
2. Replace the lower control if the error  
code persists.  
20  
CONTROL DISPLAY TROUBLESHOOTING  
CONTROL DISPLAY STATUS  
PROBLEM  
SOLUTION  
1. Clean the screen on the combustion air  
intake chamber. Turn the power “OFF” for  
10 to 20 seconds then “ON” again to clear  
the error code. If the problem persists:  
2. Ensure the pressure switch sensing tube  
is in good condition and securely  
connected at both ends.  
6.  
“P-SW”, “OPEN”, and “CLEAN SCREEN” Flashing  
The air pressure switch contacts  
remain open longer than 11  
seconds after the combustion fan  
is energized.  
3. Ensure the inner door to the combustion  
chamber is secure and the gasket is  
properly sealing.  
4. Check operation of the air intake chamber  
fan and pressure switch.  
A. Turn off power to the water heater.  
B. Remove the tubing from the pressure  
switch and the wires from both  
terminals of the pressure switch.  
C. Connect a digital manometer to the  
open end of the tubing from the air  
intake chamber. Turn on the power to  
the water heater and when the fan turns  
on, measure the pressure reading in the  
tubing. If the pressure reading reaches  
the .22” WC make point of the pressure  
switch, turn off power to the water  
heater and reconnect tubing to the  
pressure switch. If pressure reading does  
not reach the .22” WC make point, check  
the system and tubing for restrictions  
and cleanliness.  
D. Attach leads of ohmmeter or continuity  
tester to the terminals of the pressure  
switch. Turn on power to the water  
heater and when the air intake fan  
comes on, check for continuity across  
the pressure switch contacts. If switch  
contacts remain open (no continuity)  
while the fan is in operation - replace  
the pressure switch.  
1. Turn off power to the water heater.  
7.  
“P-SW” and “SHORT” Flashing  
The air pressure switch contacts  
remain closed for more than 5  
seconds when they should be  
open.  
2. Locate the pressure switch wiring –  
ensure pressure switch wiring is correct  
and not jumped.  
3. Remove wires to both terminals on  
pressure switch.  
4. Check pressure switch contacts with an  
ohmmeter for continuity.  
A. If pressure switch contacts show  
continuity (closed circuit) replace  
the pressure switch.  
B. If pressure switch contacts show  
open circuit and all wiring is correct  
– replace the lower control.  
1. Check all wiring to the hot surface ignitor.  
8.  
“IGN” Flashing  
Open ignitor circuit  
2. Check the 3 pin Molex ignitor assembly  
plug and receptacle on the lower control  
for a good connection. Repair or replace  
parts if necessary.  
3. Check resistance of the ignitor with an  
ohmmeter on the ignitor assembly plug.  
Replace ignitor if resistance is not within  
1.72 and 2.40 ohms.  
4. If above checks are good – turn off  
power for 10 seconds and then back on.  
If this error code will not clear and the  
ignitor resistance is within specifications  
– replace the lower control.  
Flammable Vapor Sensor has  
detected the presence of  
flammable vapors and is in lockout  
1. Do not touch any electrical switch, do not use  
any phone in the building and do not try to  
light any appliance.  
9.  
“FV-SENSE” Flashing  
2. Smell around the water heater to ensure there  
are no gas leaks at the gas control valve or in  
the supply gas line or for any other type of  
flammable vapors in the area.  
3. Carefully inspect the area surrounding the  
water heater for any substances such as gas-  
oline, paint, paint thinners, varnish, or cleaners  
that could emit flammable vapors. Remove  
anything that can potentially emit flammable  
vapors from the area and store it properly in a  
different location.  
~ continued next page ~  
21  
CONTROL DISPLAY TROUBLESHOOTING  
CONTROL DISPLAY STATUS  
PROBLEM  
SOLUTION  
4. System must be manually reset by entering a  
special FVS reset sequence into the Electronic  
Control Display. See Electronic Control  
9.  
“FV-SENSE” Flashing  
(Continued from previous page)  
Display - FV - Sense Reset Sequence for  
instructions. It is also recommended that the  
FV Sensor be replaced.  
The air pressure switch contacts  
remain open longer than 5  
seconds after the combustion fan  
is energized.  
1. Clean the screen on the combustion air  
intake chamber, retest.  
10.  
11.  
“LDO-SW”, “OPEN”, and “CLEAN SCREEN”  
Flashing  
2. If the problem persists: Cycle power to the  
water heater “OFF” and “ON” to reset.  
1. Check all wiring to the flammable vapor  
sensor.  
“FV-SENSE” and “OPEN” Flashing  
Flammable Vapor Sensor is open  
2. Remove the connectors from the  
flammable vapor sensor and measure  
the resistance of the sensor with an  
ohmmeter.  
A. If the reading taken is more than  
1.7 million ohms, replace the  
flammable vapor sensor.  
B. If the reading taken is less than 1.7  
million ohms, and the wiring from  
the control to the sensor is good,  
replace the lower control.  
1. Check all wiring to the flammable vapor  
sensor.  
12.  
“FV-SENSE” and “SHORT” Flashing  
Flammable Vapor Sensor is  
shorted  
2. Remove the connectors from the  
flammable vapor sensor and measure  
the resistance of the sensor with an  
ohmmeter.  
A. If the reading taken is less than  
2000 ohms, replace the flammable  
vapor sensor.  
B. If the reading taken is more than  
2000 ohms, and the wiring from the  
control to the sensor is good,  
replace the lower control.  
1. Turn power off for 10 to 20 seconds then  
on again to clear this error code.  
13.  
14.  
15.  
“THMSTR” and “OPEN” Flashing  
“THMSTR” and “SHORT” Flashing  
All Segments Flashing  
The self-diagnostic test has  
detected the temperature sensor  
(thermistor) inside the immersion  
probe is open.  
2. This part of the control cannot be  
replaced or serviced. If the error code  
cannot be cleared, the lower control must  
be replaced.  
1. Turn power off for 10 to 20 seconds then  
on again to clear this error code.  
The self-diagnostic test has  
detected the temperature sensor  
(thermistor) inside the immersion  
probe is shorted.  
2. This part of the control cannot be  
replaced or serviced. If the error code  
cannot be cleared, the lower control must  
be replaced.  
1. Press and release each of the  
The self-diagnostic check has  
detected one or both of the  
temperature adjustment buttons  
are stuck.  
temperature adjustment buttons. If the  
above action does not clear the error, the  
control will continue to regulate the water  
temperature at the last setting. However,  
settings will no longer be adjustable – the  
upper control should be replaced.  
1. Check the wire that runs from the power  
anode to the upper control. Check the  
wire for damage, and to ensure that the  
connectors are fully seated into the  
mating connectors on both ends.  
16.  
“P-ANODE” and “OPEN” Flashing  
No current to Power Anode.  
2. Check that the tank is full of water. Never  
use this water heater unless it is  
completely full of water. To prevent  
damage to the tank, the tank must be  
filled with water. Water must flow from  
the hot water faucet before turning “ON”  
gas to the water heater.  
3. Cycle power to the water heater “OFF” and  
“ON” to reset.  
1. Turn the power off for 10 to 20 seconds  
then on again to clear the error code.  
17.  
“P-ANODE” Flashing  
Power Anode circuit failure.  
2. If the error code persists or cannot be  
cleared, replace the upper control.  
22  
TROUBLESHOOTING FLOWCHART  
APPLY POWER TO  
APPLIANCE  
NO  
REQUEST  
FOR HEAT  
PRESENT?  
3 MINUTE  
AUTOMATIC RESET  
TIME DELAY  
YES  
WAIT FOR PRESSURE  
SWITCH TO OPEN  
DISPLAY ERROR  
IS  
NO  
PRESSURE SWITCH  
PROVEN OPEN WITHIN  
NUMBER  
7
5
SECONDS?  
YES  
COMBUSTION  
FAN ON  
IS  
WAIT FOR PRESSURE  
SWITCH TO OPEN  
DISPLAY ERROR  
NO  
PRESSURE SWITCH  
PROVEN OPEN WITHIN  
5
SECONDS?  
NUMBER  
7
IS  
WAIT FOR PRESSURE  
SWITCH TO CLOSE  
DISPLAY ERROR  
YES  
NO  
PRESSURE SWITCH  
PROVEN CLOSED  
WITHIN 11  
NUMBER  
6
SECONDS?  
ONE HOUR  
AUTOMATIC RESTART  
TIME DELAY  
YES  
PREPURGE  
COMBUSTION FAN  
OFF  
TURN OFF  
COMBUSTION FAN,  
DISPLAY ERROR CODE  
NO  
IS  
IGNITOR  
OKAY?  
NUMBER  
8
YES  
IGNITOR ON FOR  
WARM-UP TIME  
TURN OFF  
COMBUSTION FAN  
AFTER POST-PURGE  
COMBUSTION  
FAN OFF  
DISPLAY ERROR  
3
GAS VALVE OPENS  
YES  
IS  
NO  
WAIT FOR PRESSURE  
SWITCH TO CLOSE  
DISPLAY ERROR  
PRESSURE SWITCH  
PROVEN CLOSED  
COMBUSTION FAN  
ON  
WITHIN  
5
NUMBER  
6
SECONDS?  
MAIN  
BURNER LIGHTS  
AND IS SENSED  
DURING TRIAL  
FOR  
YES  
NO  
LESS  
GAS VALVE CLOSES  
INTERPURGE  
THAN  
3
TRIES  
FOR IGNITION?  
IGNITION  
NO  
YES  
IGNITOR TURNS OFF  
YES  
LOST  
IS  
YES  
GAS VALVE CLOSES  
FLAME SENSE  
LOST?  
LESS THAN  
TIMES?  
4
NO  
NO  
IS  
WAIT FOR PRESSURE  
SWITCH TO CLOSE  
DISPLAY ERROR  
NO  
PRESSURE SWITCH  
PROVEN CLOSED  
WITHIN  
SECONDS?  
5
NUMBER  
6
Please Note:  
The control continually monitors  
YES  
internal circuits and external sensors.  
Error codes noted above, and those for  
self-diagnostic faults can be found on  
pages 20 through 22.  
YES  
IS  
COMBUSTION FAN  
OFF AFTER POST-  
PURGE DELAY  
REQUEST FOR HEAT  
SATISFIED?  
GAS VALVE OFF  
NO  
23  
EXTERNAL INSPECTION AND CLEANING  
Cleaning the Air Intake Chamber Screen:  
Figure 24.  
• At least twice annually the air intake chamber  
screen should be inspected for any dust or  
debris that may have accumulated on the  
louvers.  
NOTE: If the water heater is located in an area  
that is subjected to lint, pet hair or dirt, it may be  
necessary to check the air intake chamber screen  
more frequently.  
• Use a vacuum cleaner with a hose attachment  
to remove any dust or debris that may have  
accumulated on the screen.  
Air Intake Chamber  
Screen  
Cleaning the Combustion Chamber and Air  
Diverter Assembly:  
Figure 25.  
• Follow procedure outlined in “Removing Inner  
Door/Manifold/Burner Assembly”, page 41.  
• Use a vacuum cleaner/shop vac to remove  
all loose debris in the combustion chamber.  
Use compressed air to clear any dust or  
debris that may have accumulated on the air  
diverter assembly.  
INNER DOOR/  
MANIFOLD/BURNER  
ASSEMBLY  
COMBUSTION  
CHAMBER  
Reassemble following the procedure under  
“Installing Inner Door/Manifold/Burner  
Assembly”, page 42.  
AIR DIVERTER  
ASSEMBLY  
24  
ELECTRONIC CONTROL DISPLAY REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 26.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Removing the Electronic Control Display:  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
HOTTER  
COOLER  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 26).  
Electronic Control Display  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 27).  
Figure 27.  
ON  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 27).  
4. Remove the electronic control display by  
squeezing in both sides of the display and  
removing from the slots in the water heater’s front  
(Figure 28).  
OFF  
ON/OFF  
SWITCH  
5. Unplug the electronic control display electrical  
connector from the back of the electronic control  
display by depressing the locking snap and pulling  
out of the electronic control display electrical  
connection, also remove the power anode wire  
connector by pulling it off of the power anode  
control display terminal (Figure 29).  
UNPLUGGED  
Installing the Electronic Control Display:  
Figure 28.  
6. Plug the power anode electrical wire terminal onto  
the power anode connector terminal (Figure 29).  
7. Insert the electronic control display electrical  
connector into the electronic control display  
electrical connection by aligning the connector  
pins (note orientation of the connector pins) and  
pressing down ensuring the electrical connector  
snap is locked into place (Figure 29).  
ELECTRONIC CONTROL DISPLAY  
TO REMOVE OR TO INSTALL,  
SQUEEZE BOTH SIDES OF THE  
CONTROL DISPLAY.  
8. Install the electronic control display onto the front  
of the water heater by squeezing both sides of  
the electronic control display inserting the prongs  
into the water heater’s slots (please note the  
orientation of the electronic control display and  
the routing the wiring inside so as not be pinched  
between the display and the water heater’s front)  
(Figure 28).  
Figure 29.  
SLOT  
SLOT  
ELECTRONIC CONTROL  
DISPLAY ELECTRICAL  
CONNECTION  
9. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 27).  
PRONG  
10. Restart the water heater by following the directions  
on the “Lighting and Operating Instructions” label  
located on the front of the water heater.  
POWER ANODE  
CONTROL DISPLAY  
TERMINAL  
25  
POWERED ANODE ROD REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 30.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
1/16  
Tools required: Ratchet with 1-  
” Socket, Pliers,  
and Teflon® Tape or an approved pipe sealant.  
Removing the Powered Anode Rod:  
HOTTER  
COOLER  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 30).  
Electronic Control Display  
Figure 31.  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 31).  
ON  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 31).  
OFF  
4. Shut off the incoming water supply to the water  
heater and open a nearby hot water faucet to  
depressurize the water tank.  
ON/OFF  
SWITCH  
5. Remove the manifold cover outer door and  
connect a hose to the drain valve and terminate it  
to adequate drain or to the exterior of the building.  
Open the drain valve and allow at least 5 gallons  
of water from the tank to drain. Close drain and  
remove hose.  
UNPLUGGED  
6. Unplug the electrical connection on top of the  
powered anode by pulling the wire connector  
up and off of the powered anode rod electrical  
connector (Figure 32).  
Figure 32.  
7. Remove the powered anode rod by using a ratchet  
1/16  
and a 1-  
” socket turning counterclockwise  
(Figure 33). Note: Figure 33 is shown exploded,  
if the socket used is short well you may have  
to remove the top male connector first before  
removing the powered anode rod.  
Powered  
Anode  
Rod  
Figure 33.  
Powered  
Anode  
Rod  
26  
Installing the Powered Anode Rod:  
Figure 34.  
8. Use Teflon® tape or an approved pipe sealant on  
threads of the new powered anode rod.  
9. Prior to installing, it will be necessary to use pliers  
to bend up approximately 90° the electrical male  
connector on the top of the powered anode rod.  
The electrical connector should be bent upward  
in order to allow the 1-1/16” deep well socket to  
pass over the connector. Note: if using a short well  
socket the male connector must first be removed  
(Figure 34 is shown exploded for clarity).  
Powered  
Anode  
Rod  
10. Place the powered anode rod in the spud (top  
of the tank) and turn clockwise until the threads  
1/16  
are hand tight. Using a ratchet and 1-  
” socket  
tighten down water tight (Torque should be  
between 65 to 120 foot pounds).  
11. Open a nearby hot water faucet to purge air from  
the water line. Fill water heater tank completely  
(Note: to assure the water heater tank is full, keep  
the hot water faucet open for 3 minutes after a  
constant flow of water is obtained).  
Figure 35.  
12. After turning off the hot water faucet, check for  
water leaks around powered anode rod and  
immediately correct any if found.  
ON  
13. Upon determining there’s no water leak at the  
newly installed powered anode rod, reconnect the  
electrical plug connector to the top of the anode  
male terminal.  
OFF  
14. Plug the electric transformer in the wall outlet and  
turn the gas supply back on to the gas control  
valve/thermostat.  
ON/OFF  
SWITCH  
15. Turn the gas control switch to the “ON” position  
(located on the side of the gas control valve/  
thermostat see Figure 35).  
16. To restart the water heater, follow the directions  
on the “Lighting and Operating Instructions” label  
located on the front of the water heater near the  
gas control valve/thermostat.  
17. Upon verifying proper operation of the water  
heater, replace the manifold cover outer door.  
Teflon® is a registered trademark of E.I. Du Pont De Numours and Company.  
27  
PRESSURE SWITCH REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 36.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: Phillips Head Screwdriver.  
Removing the Pressure Switch:  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 36).  
HOTTER  
COOLER  
Electronic Control Display  
Figure 37.  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 37).  
ON  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 37).  
OFF  
4. Remove the manifold cover/ outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
ON/OFF  
SWITCH  
5. Remove the air pressure tubing from the air  
pressure switch by pulling downward on the  
tubing at the connection to the air pressure switch  
(Figure 38).  
6. Remove the two (2) electrical flag terminals from  
the switch by pulling outward and off of the switch  
(Figure 39).  
UNPLUGGED  
Figure 38.  
7. Using a phillips head screwdriver, remove the 2  
screws securing the pressure switch to the water  
heater’s side (keep these screws in a safe place  
for reinstallation later) (Figure 39).  
PRESSURE SWITCH  
TUBING CONNECTION  
Installing the Pressure Switch:  
8. Secure the new pressure switch to the water  
heater’s side by reusing the 2 screws removed in  
step 7 (Figure 39).  
9. Reattach the two (2) electrical flag terminals  
by pushing the flag terminals onto the switch  
(Figure 39).  
Figure 39.  
10. Reattach the air pressure tubing to the air  
pressure switch by pushing the tubing onto the  
connector until the end of the tubing pushes to the  
shoulder of the connector (Figure 38).  
SCREW  
PRESSURE  
SWITCH  
11. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 37).  
FLAG  
TERMINALS  
12. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater.  
13. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
AIR PRESSURE  
TUBING  
28  
TRANSFORMER REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement parts.  
Figure 40.  
If you lack the necessary skills to properly perform the  
installation, you should not proceed, but get help from a  
qualified service technician.  
5/16  
5/16  
Tools required: Ratchet with  
” Socket or  
” Nut  
Driver, Phillips Head Screwdriver.  
Removing the Transformer:  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 40).  
HOTTER  
COOLER  
Electronic Control Display  
Figure 41.  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 41).  
ON  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 41).  
OFF  
4. Remove the manifold cover outer door from the  
heater by depressing on the lower portion and  
pulling outward.  
ON/OFF  
SWITCH  
5. Unplug the power supply transformer connector  
from the bottom of the gas control valve by  
pressing the snap connector and pulling  
downward (Figure 42). (NOTE: The transformer is  
located inside the transformer box adjacent to the  
gas control/thermostat valve).  
UNPLUGGED  
6. Using a phillips head screwdriver, remove the  
transformer box from the side of the water heater  
by removing the single screw securing it to the  
water heater’s side (Note: keep screw in a safe  
place for reinstalling later).  
Figure 43.  
GROUND  
SCREW  
ELECTRICAL  
FLAG TERMINALS  
7. Using a phillips head screwdriver remove the  
ground screw from the inside of the transformer  
box (Note: save the screw for reinstallation later)  
(see Figure 43).  
TRANSFORMER  
BOX  
8. Take note of the position of the transformer, use  
a 5/16” nut driver or a ratchet with a 5/16” socket  
to remove the 2 hex head screws on the front of  
the transformer box (Note: save the screws for  
reinstallation later) (see Figure 43).  
TRANSFORMER  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
HEX HEAD  
SCREWS  
WIRE  
PROTECTOR  
9. Unplug the two flag terminal electrical connections  
on the transformer and pull the wiring and  
connector through the wire protector (Figure 43).  
Figure 42.  
GAS CONTROL  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
VALVE/THERMOSTAT  
ELECTRICAL  
FLAG  
TERMINALS  
GROUND  
SCREW  
POWER SUPPLY  
TRANSFORMER  
WIRE  
PROTECTOR  
CONNECTOR  
TRANSFORMER  
29  
Installing the New Transformer:  
Figure 44.  
10. Insert the wiring connector that goes to the gas  
control valve/thermostat through the wire protector  
on the side of the transformer box (Figure 44).  
GROUND  
SCREW  
ELECTRICAL  
FLAG TERMINALS  
11. Attach the two (2) flag terminal connectors to  
the transformer by aligning and pressing down  
(Figure 44).  
TRANSFORMER  
BOX  
12. Position the new transformer inside the  
transformer box where the wiring connections are  
nearest their exit points (Figure 44).  
TRANSFORMER  
13. Align the holes of the transformer mounting  
bracket to the hole of the transformer box and  
attach using the 2 hex head screws (Note:  
take care not to pinch any wiring between the  
transformer and the transformer box) (see  
Figure 44).  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
HEX HEAD  
SCREWS  
WIRE  
PROTECTOR  
14. Insert the ground wire connector through the  
ground screw and tighten in place with a phillips  
head screwdriver (Figure 44).  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
15. Using the screw removed in step 6, reattach the  
transformer box to the water heater’s side.  
ELECTRICAL  
FLAG  
TERMINALS  
GROUND  
SCREW  
16. Reattach the power supply transformer connector  
to the bottom of the gas control valve/thermostat  
by aligning and pushing upward (Figure 42).  
WIRE  
PROTECTOR  
17. Plug the electric transformer in the wall outlet and  
turn the gas supply back on to the gas control  
valve/thermostat (Figure 41).  
TRANSFORMER  
18. Turn the gas control switch to the “ON” position  
(Figure 41).  
19. To restart the water heater, follow the directions  
on the “Lighting and Operating Instructions” label  
located on the front of the water heater near the  
gas control valve/thermostat.  
20. Upon verifying proper operation of the water  
heater, replace the manifold cover outer door.  
30  
AIR INTAKE CHAMBER BOX REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 45.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: Phillips Head Screwdriver.  
Removing the Air Intake Chamber Box:  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 45).  
HOTTER  
COOLER  
Electronic Control Display  
Figure 46.  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 46).  
ON  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 46).  
OFF  
4. Remove the manifold cover/ outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
ON/OFF  
SWITCH  
5. Unplug the 3-wire pressure switch/fan/sensor  
electrical connection of the wiring harness from  
the gas control valve/thermostat by depressing the  
lower portion of the snap clip to open and pulling  
down the connector (Figure 47).  
UNPLUGGED  
6. Using a phillips head screwdriver remove the 2  
screws of the air intake chamber screen (Note:  
save screws for reinstallation later) (Figure 48).  
Figure 47.  
7. Remove the air intake chamber screen by lifting  
upward and outward (Figure 48).  
GAS CONTROL  
VALVE/THERMOSTAT  
8. Please take note of the wire position routing  
around the fan inside the air intake chamber as  
this wire positioning will need to be duplicated  
upon installation of the fan in the new intake  
chamber box.  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
9. Remove the 2 screws securing the fan inside  
the chamber (Note: save these screws for  
reinstallation later) (Figure 48).  
10. Lift the fan up and outward to remove from the air  
intake chamber (Figure 48).  
RUBBER WIRE  
PROTECTOR  
Figure 48.  
11. Locate the male to female electrical connection  
with close pin lock on wiring harness (the  
white connection approximately 12” from fan)  
(Figure 48).  
SCREEN  
FAN  
12. To separate the electrical connection of the fan  
and wiring harness: press down on the back  
portion of the close pin lock of the electrical  
connection while pulling the connection in the  
opposite directions.  
AIR INTAKE  
CHAMBER BOX  
13. Using a phillips head screwdriver, remove the 4  
screws securing the air intake chamber box to the  
water heater’s side (also keeping these screws in  
a safe place for reinstallation later) (Figure 48).  
31  
14. Rotate the top of the air intake chamber box from  
left to right (only a few inches in both directions)  
while pulling outward at the bottom removing  
the air intake chamber box from the combustion  
chamber pipe saving the air intake chamber  
gasket for reinstallation (Figure 49).  
Figure 49.  
AIR INTAKE  
CHAMBER BOX  
REMOVAL  
ROTATE FROM  
LEFT TO RIGHT  
15. Unplug the air pressure tubing from the back of  
the old air intake chamber box (Figure 50).  
AND  
16. The wire harness goes through the rubber wire  
protector in the back of the air intake chamber box  
(Figure 50).  
PULL OUTWARD  
17. Reach inside the air intake chamber box and push  
on the center of the rubber wire protector pushing  
it and the wiring harness wires to the outside of  
the air intake chamber box.  
CHAMBER GASKET  
Figure 50.  
RUBBER WIRE  
PROTECTOR  
18. Remove the wiring harness from the wire  
channeling in the back center of the air intake  
chamber box. The old air intake chamber box is  
now separated and can be discarded (Figure 50).  
WIRE HARNESS INSIDE  
WIRE CHANNELING  
REAR SIDE OF  
THE AIR INTAKE  
CHAMBER BOX  
Installing the Air Intake Chamber Box:  
AIR PRESSURE TUBING  
CONNECTION  
19. Insert the fan wiring harness wire through the  
back and into the fan box compartment by  
threading the connector through the opening and  
insert in approximately 6 inches of wiring (up to  
the rubber wire protector) (Figure 50).  
20. Push the rubber wire protector into place in the  
back of the air intake chamber box (Note: the  
rubber wire protector must be positioned properly  
and locked into place around both sides of the air  
intake chamber box) (Figure 50).  
Figure 51.  
REINSTALL  
CHAMBER GASKET  
21. Position the wiring harness wire in the wiring  
channeling molded down the back center of the air  
intake chamber box (Figure 50).  
22. Connect the air pressure tubing to the fitting  
on the air intake chamber box and route tubing  
in molded inlaid of the air intake chamber box  
(Figure 50).  
NEW AIR INTAKE  
CHAMBER BOX  
23. Reinstall the air intake chamber gasket (removed  
in step 14) on the back lower portion of the new air  
intake chamber box (Figure 51).  
Figure 52.  
AIR INTAKE  
CHAMBER BOX  
INSTALLATION  
24. Install the new air intake chamber box to the  
combustion chamber pipe. Using a small amount  
of soapy water will help. Do not get any water  
or soapy water on any electrical connections or  
gas control components (see Figure 52). (NOTE:  
UNDUE PRESSURE OR SUDDEN FORCE  
SUCH AS HAMMERING OR BEATING ON  
THE AIR CHAMBER BOX WITH ANY OBJECT  
INCLUDING YOUR HANDS WILL DAMAGE THE  
AIR INTAKE CHAMBER BOX AND RESULT IN  
FAILURE TO THE HEATER’S OPERATION.  
ROTATE FROM  
LEFT TO RIGHT  
AND  
PUSH INWARD  
32  
25. Install the air intake chamber box by rotating  
the top of the air intake chamber box from left to  
right (only a few inches in both directions) while  
pressing on the bottom portion of the air intake  
chamber box. When properly installed the air  
intake chamber box will be in place against the  
water heater’s side aligning with the screw holes.  
Figure 53.  
SECURE WITH  
SCREWS REMOVED  
EARLIER  
26. Secure the air intake chamber box to the water  
heater’s side by reusing the 4 screws removed in  
step 13 (Figure 53).  
Figure 54.  
Installing the Fan in the Air Intake Chamber Box:  
27. Plug the electrical connections of the fan into the  
wiring harness: Align the electrical connections in  
such a position as to ensure the locking portions  
of the connections are on the same side. Gently  
push the electrical connectors together until the  
snap lock on the wiring harness engages the  
angular lock on the fan connector. Do Not use  
undue force in pushing these connectors together  
(Figure 54). (Note: Connectors are designed in  
such a manner if the connection is not properly  
aligned they will not lock together).  
FAN  
GENTLY PUSH THE ELECTRICAL  
CONNECTORS TOGETHER UNTIL  
IT IS SNAP LOCKED.  
28. Replace the fan inside the air intake chamber  
box. It is imperative that the square portion of the  
fan air outlet be placed inside the raised square  
portion of the air intake chamber fan compartment  
(Figure 55).  
Figure 55.  
INSTALL THE FAN USING THE  
TWO SCREWS REMOVED  
EARLIER.  
29. Ensuring the fan is properly aligned in the air  
intake chamber, secure the fan in place using the  
2 screws removed in step 9 (Figure 55).  
FAN  
30. Route the wiring inside the fan box to the outer  
edge of the fan in such a manner to ensure it will  
not be pinched or damaged upon installation of  
the air intake screen (Figure 55).  
31. Install the air intake chamber screen, ensuring that  
the prongs of the lower portion of the air intake  
chamber screen are in place in the holding slots.  
Using the 2 screws removed in step 6, secure the  
air intake chamber screen (Figure 56).  
Figure 56.  
32. Reattach the 3-wire wiring harness connector to  
the gas control valve (Figure 47).  
33. Check the air hose tubing connection to the  
pressure switch to ensure the tubing has not  
loosen up or pulled off.  
INSTALL THE AIR INTAKE  
CHAMBER SCREEN.  
34. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 46).  
35. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater.  
36. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
33  
WIRING HARNESS REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 57.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: Phillips Head Screwdriver.  
Removing the Air Intake Chamber Box:  
HOTTER  
COOLER  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 57).  
Electronic Control Display  
Figure 58.  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 58).  
ON  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 58).  
OFF  
4. Remove the manifold cover/ outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
ON/OFF  
SWITCH  
5. Unplug the 3-wire pressure switch/fan/sensor  
electrical connection of the wiring harness from  
the gas control valve/thermostat by depressing the  
lower portion of the snap clip to open and pulling  
down the connector (Figure 59).  
UNPLUGGED  
6. Unplug the electric flag terminals and air pressure  
tubing from the pressure switch (Figure 60).  
Figure 59.  
7. Remove the FV sensor by depressing the snap  
lock to open the FV sensor cover, slide the FV  
sensor out of the cover and unplug the electrical  
flag terminals connections (Note: place the FV  
sensor in a safe place as it will be reinstalled later)  
(Figure 60).  
GAS CONTROL  
VALVE/THERMOSTAT  
8. Using a phillips head screwdriver remove the 2  
screws of the air intake chamber screen (Note:  
save screws for reinstallation later) (Figure 62).  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
9. Remove the air intake chamber screen by lifting  
upward and outward (Figure 62).  
10. Please take note of the wire position routing  
around the fan inside the air intake chamber as  
this wire positioning will need to be duplicated  
upon installation of the new wiring harness  
(Figure 62).  
Figure 60.  
PRESSURE  
SWITCH  
11. Using a phillips head screwdriver, remove the 4  
screws securing the air intake chamber box to the  
water heater’s side (also keeping these screws in  
a safe place for reinstallation later) (Figure 61).  
12. Rotate the top of the air intake chamber box from  
left to right (only a few inches in both directions)  
while pulling outward at the bottom removing  
the air intake chamber box from the combustion  
chamber pipe saving the air intake chamber  
gasket for reinstallation (Figure 61).  
PRESSURE TUBING & WIRING  
HARNESS FLAG TERMINALS  
FV SENSOR  
34  
Replacing the Wiring Harness:  
Figure 61.  
AIR INTAKE  
CHAMBER BOX  
REMOVAL  
13. Locate the male to female electrical connection  
with close pin lock on wiring harness (located on  
the right side of fan) (Figure 62).  
REMOVE SCREWS  
ROTATE FROM  
LEFT TO RIGHT  
14. To separate the electrical connection of the fan  
and wiring harness: press down on the back  
portion of the close pin lock of the electrical  
connection while pulling the connection in the  
opposite directions.  
AND  
PULL OUTWARD  
15. The wire harness goes through the rubber wire  
protector in the back of the air intake chamber box  
(Figure 62).  
CHAMBER GASKET  
16. Reach inside the air intake chamber box and push  
on the center of the rubber wire protector pushing  
it and the wiring harness wires to the outside of  
the air intake chamber box (Figure 62).  
Figure 62.  
RUBBER WIRE  
PROTECTOR  
17. Remove the wiring harness from the wire  
channeling in the back center of the air intake  
chamber box (Figure 63).  
ELECTRICAL  
CONNECTION  
18. The old wiring harness can now be discarded.  
AIR INTAKE  
CHAMBER SCREEN.  
Installing the New Wiring Harness:  
19. Route the multi-lead portion of the new wiring  
harness through the opening at the bottom of the  
water heater’s jacket (Figure 64).  
Figure 63.  
RUBBER WIRE  
PROTECTOR  
20. Insert the fan wiring harness wire through the  
back and into the fan box compartment by  
threading the connector through the opening and  
insert in approximately 6 inches of wiring (up to  
the rubber wire protector) (Figure 62).  
21. Push the rubber wire protector into place in the  
back of the air intake chamber box (Note: The  
rubber wire protector must be positioned properly  
and locked into place around both sides of the air  
intake chamber box) (Figure 63).  
WIRE HARNESS INSIDE  
WIRE CHANNELING  
REAR SIDE OF  
THE AIR INTAKE  
CHAMBER BOX  
22. Position the wiring harness wire in the wiring  
channeling molded down the back center of the air  
intake chamber box (Figure 63).  
23. Plug the electrical connections of the fan into the  
wiring harness: Align the electrical connections in  
such a position as to ensure the locking portions  
of the connections are on the same side. Gently  
push the electrical connectors together until the  
snap lock on the wiring harness engages the  
angular lock on the fan connector. Do Not use  
undue force in pushing these connectors together  
(Figure 62). (Note: Connectors are designed in  
such a manner if the connection is not properly  
aligned they will not lock together).  
AIR PRESSURE TUBING  
CONNECTION  
Figure 64.  
ROUTE WIRING HARNESS  
THROUGH OPENING AT  
BOTTOM OF JACKET.  
24. Route the wiring inside the fan box to the outer  
edge of the fan in such a manner to ensure it will  
not be pinched or damaged upon installation of  
the air intake screen (Figure 62).  
35  
25. Install the air intake chamber screen, ensuring that  
the prongs of the lower portion of the air intake  
chamber screen are in place in the holding slots.  
Using the 2 screws removed in step 8, secure the  
air intake chamber screen (Figure 65).  
Figure 65.  
26. Check the air pressure tubing to the fitting on the  
of the air intake chamber box and route tubing  
in molded inlaid of the air intake chamber box  
(Figure 63).  
INSTALL THE AIR INTAKE  
CHAMBER SCREEN.  
27. Reinstall the air intake chamber gasket (removed  
in step 12) on the back lower portion of the new air  
intake chamber box (Figure 66).  
28. Install the new air intake chamber box to the  
combustion chamber pipe. Using a small amount  
of soapy water will help. Do not get any water  
or soapy water on any electrical connections  
or gas control components (Figure 67). NOTE:  
UNDUE PRESSURE OR SUDDEN FORCE  
SUCH AS HAMMERING OR BEATING ON  
THE AIR CHAMBER BOX WITH ANY OBJECT  
INCLUDING YOUR HANDS WILL DAMAGE THE  
AIR INTAKE CHAMBER BOX AND RESULT IN  
FAILURE TO THE HEATER’S OPERATION.  
Figure 66.  
REINSTALL  
CHAMBER GASKET  
29. Install the air intake chamber box by rotating  
the top of the air intake chamber box from left to  
right (only a few inches in both directions) while  
pressing on the bottom portion of the air intake  
chamber box. When properly installed the air  
intake chamber box will be in place against the  
water heater’s side aligning with the screw holes  
(Figure 67).  
AIR INTAKE  
CHAMBER BOX  
30. Secure the air intake chamber box to the water  
heater’s side by reusing the 4 screws removed in  
step 11 (Figure 67).  
Figure 67.  
31. Plug in the electrical flag terminals into the air  
pressure switch (Figure 60).  
32. Reinstall the FV sensor removed in step 7, by  
depressing the snap lock to open the FV sensor  
cover, route wiring through sensor cover, plug the  
electrical flag terminals connections to the FV  
sensor and slide the FV sensor back inside and  
close the cover (Figure 60).  
INSTALL SCREWS  
ROTATE FROM  
LEFT TO RIGHT  
33. Connect the air pressure tubing to the pressure  
switch (Figure 60).  
AND  
34. Attach the 3-wire wiring harness connector to the  
gas control valve (Figure 59).  
PUSH INWARD  
35. Check the air hose tubing connection to the  
pressure switch to ensure the tubing has not  
loosened up or pulled off (Figure 60).  
36. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 58).  
37. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater.  
38. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
36  
AIR INTAKE CHAMBER FAN REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 68.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: Phillips Head Screwdriver.  
HOTTER  
COOLER  
Electronic Control Display  
Removing the Fan from the Air Intake Chamber:  
Figure 69.  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 68).  
ON  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 69).  
OFF  
ON/OFF  
SWITCH  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 69).  
4. Using a phillips head screwdriver, remove the two  
(2) screws at the air intake chamber screen (Note:  
save screws for reinstallation later) (Figure 70).  
UNPLUGGED  
5. Remove the air intake chamber screen by lifting  
upward (Figure 70).  
Figure 70.  
6. Take note of the wire position routing around  
the fan inside of the air intake chamber as this  
wire positioning will need to be duplicated upon  
installation of the new fan inside the intake  
chamber box.  
7. Remove the 2 screws securing the old fan  
inside the chamber (Note: save these screws for  
reinstallation later) (Figure 70).  
SCREEN  
8. Lift the old fan up and outward to remove from the  
air intake chamber (Figure 70).  
FAN  
9. Locate the male to female electrical connection  
with close pin lock on wiring harness (the white  
connection approximately 12” from fan).  
10. To separate the electrical connection of the fan  
and wiring harness: press down on the back  
portion of the close pin lock of the electrical  
connection while pulling the connection in the  
opposite directions.  
AIR INTAKE  
CHAMBER BOX  
37  
Installing the Fan in the Air Intake Chamber Box:  
Figure 71.  
11. Plug the electrical connections of the new fan  
into the wiring harness: Align the electrical  
connections in such a position as to ensure the  
locking portions of the connections are on the  
same side. Gently push the electrical connectors  
together until the snap lock on the wiring  
harness engages the angular lock on the fan  
connector. Do Not use undue force in pushing  
these connectors together (Figure 71). (Note:  
Connectors are designed in such a manner if the  
connection is not properly aligned they will not  
lock together).  
FAN  
GENTLY PUSH THE ELECTRICAL  
CONNECTORS TOGETHER UNTIL  
IT IS SNAP LOCKED.  
12. Place the new fan inside the air intake chamber  
box. It is imperative that the square portion of  
the fan air outlet be placed inside the raised  
square portion of the air intake chamber of the fan  
compartment (Figure 72).  
Figure 72.  
13. Ensuring the new fan is properly aligned in the air  
intake chamber, secure the fan in place using the  
2 screws removed in step 7 (Figure 72).  
INSTALL THE FAN USING THE  
TWO SCREWS REMOVED  
EARLIER.  
FAN  
14. Route the wiring inside the fan box to the outer  
edge of the fan in such a manner to ensure it will  
not be pinched or damaged upon installation of  
the air intake screen (Figure 72).  
15. Install the air intake chamber screen, ensuring that  
the prongs of the lower portion of the air intake  
chamber screen are in place in the holding slots.  
Using the 2 screws removed in step 4, secure the  
air intake chamber screen (Figure 73).  
Figure 73.  
16. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 69).  
17. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater.  
INSTALL THE AIR INTAKE  
CHAMBER SCREEN.  
18. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
38  
PRESSURE TUBING REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 74.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: Phillips Head Screwdriver.  
HOTTER  
COOLER  
Electronic Control Display  
Removing the Air Intake Chamber Box:  
Figure 75.  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 74).  
ON  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 75).  
OFF  
ON/OFF  
SWITCH  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 75).  
4. Remove the manifold cover/ outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
UNPLUGGED  
5. Remove the air pressure tubing from the air  
pressure switch by pulling downward on the  
tubing at the connection to the air pressure switch  
(Figure 76).  
Figure 76.  
6. Using a phillips head screwdriver, remove the 4  
screws securing the air intake chamber box to the  
water heater’s side (Note: keep these screws in a  
safe place for reinstallation later) (Figure 77).  
PRESSURE SWITCH  
TUBING CONNECTION  
7. Rotate the top of the air intake chamber box from  
left to right (only a few inches in both directions)  
while pulling outward at the bottom removing  
the air intake chamber box from the combustion  
chamber pipe saving the air intake chamber  
gasket for reinstallation (Figure 77).  
8. Upon removal of the air intake chamber box,  
locate the air pressure tubing at the back of the air  
intake chamber box and unplug the tubing. Note  
the routing of the air pressure tubing through the  
water heater’s opening near the bottom. Remove  
the old air pressure tubing (Figures 76 & 77).  
Figure 77.  
ROTATE FROM  
LEFT TO RIGHT  
SCREWS  
9. Connect the new air pressure tubing into the back  
of the air intake chamber box by pushing it on the  
connector (Figure 78).  
AIR PRESSURE  
TUBING  
AND  
10. Route the new air pressure tubing through the  
water heater’s opening near the bottom (Note:  
mirrors the position of the old tubing) (Figures 77).  
PULL OUTWARD  
CHAMBER GASKET  
39  
Installing the Air Intake Chamber Box:  
Figure 78.  
RUBBER WIRE  
PROTECTOR  
11. Check the position the wiring harness wire in the  
wiring channeling molded down the back center of  
the air intake chamber box (Figure 78).  
12. Connect the air pressure tubing to the fitting on  
the bottom of the air intake chamber box and route  
tubing in molded inlaid of the air intake chamber  
box (Figure 78).  
WIRE HARNESS INSIDE  
WIRE CHANNELING  
REAR SIDE OF  
THE AIR INTAKE  
CHAMBER BOX  
13. Reinstall the air intake chamber gasket (removed  
in step 7) on the back lower portion of the air  
intake chamber box (Figure 79).  
AIR PRESSURE TUBING  
CONNECTION  
14. Install the air intake chamber box to the  
combustion chamber pipe. Using a small amount  
of soapy water will help. Do not get any water  
or soapy water on any electrical connections or  
gas control components (see Figure 80), (NOTE:  
UNDUE PRESSURE OR SUDDEN FORCE  
SUCH AS HAMMERING OR BEATING ON  
THE AIR CHAMBER BOX WITH ANY OBJECT  
INCLUDING YOUR HANDS WILL DAMAGE THE  
AIR INTAKE CHAMBER BOX AND RESULT IN  
FAILURE OF THE HEATER’S OPERATION).  
Figure 79.  
REINSTALL  
CHAMBER GASKET  
NEW AIR INTAKE  
CHAMBER BOX  
15. Install the air intake chamber box by rotating  
the top of the air intake chamber box from left to  
right (only a few inches in both directions) while  
pressing on the bottom portion of the air intake  
chamber box. When properly installed the air  
intake chamber box will be in place against the  
water heater’s side aligning with the screw holes  
(Figure 80).  
Figure 80.  
16. Secure the air intake chamber box to the water  
heater’s side by reusing the 4 screws removed in  
step 6 (Figure 80).  
ROTATE FROM  
LEFT TO RIGHT  
17. Reattach the air pressure tubing to the air  
pressure switch by pushing the tubing onto the  
connector until the end of the tubing pushes to the  
shoulder of the connector.  
AND  
PUSH INWARD  
18. Check the air hose tubing connection to the  
pressure switch to ensure the tubing has not  
loosened up or pulled off.  
19. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 75).  
20. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater.  
21. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
40  
INNER DOOR/MANIFOLD/BURNER ASSEMBLY REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 81.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: 3/4” Open-End Wrench or Crescent  
Wrench, Phillips Head Screwdriver, Ratchet with 1/4”  
socket or 1/4” Nut Driver.  
HOTTER  
COOLER  
Electronic Control Display  
Figure 82.  
Removing Old Inner Door/Manifold/Burner Assembly:  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 81).  
ON  
OFF  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 82).  
ON/OFF  
SWITCH  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 82).  
4. Remove the manifold cover/ outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
UNPLUGGED  
5. Unplug all the electrical connections from the  
bottom of the gas control valve/thermostat  
(Figure 83).  
Figure 83.  
6. Disconnect the electrical flag terminals and air  
pressure tubing to the pressure switch (Figure 84).  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
7. Using a 3/4” open end wrench or a crescent  
wrench remove the manifold tube from the gas  
control valve/thermostat (turning counterclockwise  
-natural gas). Grasp the manifold tube and push  
down slightly to free the manifold tube from the  
gas control valve/thermostat (Figure 83).  
GAS CONTROL  
VALVE/THERMOSTAT  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
8. Use a 1/4” nut driver or 1/4” socket & ratchet to  
loosen the 2 hex head screws on the inner door  
so the inner door/manifold/burner assembly can  
be removed (Figure 85).  
SENSE  
CONNECTOR  
DISPLAY, ANODE  
ROD CONNECTOR  
Figure 84.  
9. Remove inner door/manifold/burner assembly by  
grasping the manifold and pulling straight back.  
Care should be taken when inner door and burner  
assembly passes through jacket opening that it  
does not damage any of the electrical wiring or  
the air pressure hose (Figure 86).  
PRESSURE  
SWITCH  
MANIFOLD  
TUBE  
41  
Installation Caution Must Be Taken:  
Figure 85.  
10. Prior to installing the new inner door/manifold/  
burner assembly, look inside the burner chamber  
to fully understand the correct positioning of the  
burner assembly and burner manifold tab. It may  
be necessary to use a flashlight to ensure correct  
placement. Care must be taken so as to not  
damage any electrical wiring, components or the  
air pressure tubing as you are installing the new  
inner door/manifold/burner assembly.  
1/4” HEX  
HEAD SCREW  
Extra caution should be taken to ensure  
that electrical wiring, air hose, fiberglass  
insulation nor any other object is between  
door gasket and combustion chamber shield.  
Installing New Inner Door/Manifold/Burner Assembly  
Figure 86.  
11. Insert the manifold/burner assembly in the burner  
chamber compartment, making sure that the tip  
of burner manifold tab engages in the slot of the  
bracket (Figure 86).  
INNER DOOR/  
MANIFOLD/BURNER  
ASSEMBLY  
The tip end of the burner manifold MUST  
be placed in the slotted portion under the  
condensation pan to obtain proper installation  
(Figure 86).  
SLOT  
12. After confirming no material of any type are  
between door gasket and combustion chamber  
shield, align the screws on the inner door with  
the screw holes on the combustion chamber and  
tighten with 1/4” nut driver or 1/4” socket & ratchet  
(Figure 85). After tightening the inner door  
screws, visually inspect area around door  
gasket and skirt for spaces or gaps. The door  
gasket MUST be sealed completely in order  
for the water heater to perform properly.  
DO NOT OPERATE THE WATER HEATER IF  
THE DOOR GASKET DOES NOT CREATE  
A SEAL BETWEEN MANIFOLD DOOR AND  
COMBUSTION CHAMBER.  
13. Reconnect the manifold tube to the gas control  
valve/thermostat (Note: Do Not apply any thread  
sealant at this connection). To prevent any cross  
threading the manifold tube should be started  
by hand (turn clockwise -natural gas). Upon  
tightening with the fingers and confirming it has  
not been cross threaded, tighten nut with an 3/4”  
open end wrench or crescent wrench (Figure 87).  
BURNER’S  
TIP END  
TAB  
Figure 87.  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
GAS CONTROL  
VALVE/THERMOSTAT  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
14. Reconnect all the electrical connections to the  
bottom of the gas control valve/thermostat, gently  
pushing each connector up snapping into place  
(Figure 87).  
Figure 88.  
15. Reconnect the electrical flag terminals and air  
pressure tubing to pressure switch (Figure 88).  
PRESSURE  
SWITCH  
16. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 82).  
17. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater. Test gas connections by brushing on an  
approved nonconcorrosive leak detection solution.  
MANIFOLD  
TUBE  
18. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
42  
FLAME SENSE/HOT SURFACE IGNITER REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 89.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: 3/4” Open-End Wrench or Crescent  
Wrench, Phillips Head Screwdriver, Ratchet with 1/4”  
socket or 1/4” Nut Driver.  
HOTTER  
COOLER  
Replacing the Flame Sense/Hot Surface Igniter  
Assembly:  
Electronic Control Display  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 89).  
Figure 90.  
ON  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 90).  
OFF  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 90).  
ON/OFF  
SWITCH  
4. Remove the manifold cover/ outer door from the  
unit by depressing on the lower portion and  
pulling outward.  
5. Remove the inner door/manifold/burner assembly.  
See Removing Inner Door/Manifold/Burner  
Assembly, (page 41) (Figure 91).  
UNPLUGGED  
6. Lift the retainer clip straight up from the back of  
the manifold component block (using a flat-blade  
screwdriver), then remove the manifold component  
block from the manifold door (Figure 92).  
Figure 91  
7. Remove and keep the screw securing the flame  
sense/hot surface igniter assembly (Figure 92).  
INNER DOOR/  
MANIFOLD/BURNER  
ASSEMBLY  
8. Remove and discard the old flame sense/hot  
surface igniter assembly.  
SLOT  
9. Route the new flame sense/hot surface igniter  
connector wire through manifold/burner door  
opening as shown in figure 92. Secure the  
assembly to the bracket ussing screw removed  
earlier.  
BURNER’S  
TIP END  
TAB  
10. Reposition the manifold component block in the  
manifold door opening and secure it with the  
retainer clip.  
Figure 92  
Screw  
11. Install inner door/manifold/burner assembly,  
(see page 42).  
Retainer Clip  
12. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater.  
Flame Sense/  
Hot Surface  
Igniter Assembly  
13. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
Manifold Component  
Block  
43  
BURNER REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 93.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: 3/4” Open-End Wrench or Crescent  
Wrench, Phillips Head Screwdriver, Ratchet with 1/4”  
socket or 1/4” Nut Driver.  
HOTTER  
COOLER  
Removing the Inner Door/Manifold/Burner Assembly:  
Electronic Control Display  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 93).  
Figure 94.  
ON  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 94).  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 94).  
4. Remove the manifold cover/outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
OFF  
ON/OFF  
SWITCH  
5. Unplug all the electrical connections from the  
bottom of the gas control valve/thermostat  
(Figure 95).  
6. Disconnect the electrical flag terminals and air  
pressure tubing to the pressure switch (Figure 96).  
7. Using a 3/4” open end wrench or a crescent  
wrench remove the manifold tube from the gas  
control valve/thermostat (turning counterclockwise  
-natural gas). Grasp the manifold tube and push  
down slightly to free the manifold tube from the  
gas control valve/thermostat (Figure 95).  
8. Use a 1/4” nut driver or 1/4” socket & ratchet to  
loosen the 2 hex head screws on the inner door  
so the inner door/manifold/burner assembly can  
be removed (Figure 97).  
UNPLUGGED  
Figure 95.  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
GAS CONTROL  
VALVE/THERMOSTAT  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
9. Remove inner door/manifold/burner assembly by  
grasping the manifold and pulling straight back.  
Care should be taken when inner door and burner  
assembly passes through jacket opening that it  
does not damage any of the electrical wiring or  
the air pressure hose (Figure 98).  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
Figure 96.  
10. Go to step 11.  
PRESSURE  
SWITCH  
MANIFOLD  
TUBE  
44  
Removing Old Burner :  
Figure 97.  
11. After noting the position of the condensation drain  
hole on the top of the burner. Turn the inner door/  
manifold/burner assembly upside. Using a phillips  
head screwdriver remove the 2 screws attaching  
the burner to the manifold pipe (saving screws for  
reinstallation later) (Figure 99).  
1/4” HEX  
HEAD SCREW  
Installing New Burner :  
12. Care MUST be taken to ensure the burner is  
installed correctly on the inner door/manifold  
assembly. Position the new burner upside down  
with the orientation of the burner’s condensation  
drain as shown in illustration (Figure 99).  
Figure 98.  
13. Align the screw holes on the inner door/manifold  
assembly. Using the two screws removed in step  
11, installed the new burner to the inner door/  
manifold assembly (rotate the assembly to visually  
check the top portion of the burner assembly and  
confirm the orientation of the condensation drain  
hole on the top of the burner is toward the back as  
shown in the illustration) (Figure 99).  
INNER DOOR/  
MANIFOLD/BURNER  
ASSEMBLY  
SLOT  
BURNER’S  
TIP END  
TAB  
Installation Caution Must Be Taken:  
14. Prior to installing the new inner door/manifold/  
burner assembly, look inside the burner chamber  
to fully understand the correct positioning of the  
burner assembly and burner manifold tab. It may  
be necessary to use a flashlight to ensure correct  
placement. Care must be taken so as to not  
damage any electrical wiring, components or the  
air pressure tubing as you are installing the new  
inner door/manifold/burner assembly.  
Figure 99.  
BURNER’S  
CONDENSATION DRAIN  
TOP VIEW  
ORIENTATION OF SCOOP  
TO BE ON THE SAME SIDE  
AS THE VIEW PORT  
VIEW PORT  
Extra caution should be taken to ensure  
that electrical wiring, air hose, fiberglass  
insulation nor any other object is between  
door gasket and combustion chamber shield.  
TWO SCREWS  
BURNER’S  
CONDENSATION DRAIN  
BOTTOM VIEW  
Reinstalling The Inner Door/Manifold/Burner Assembly  
15. Insert the manifold/burner assembly in the burner  
chamber compartment, making sure that the tip  
of burner manifold tab engages in the slot of the  
bracket (Figure 98).  
Figure 100.  
The tip end of the burner manifold MUST  
be placed in the slotted portion under the  
condensation pan to obtain proper installation  
(Figure 98).  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
GAS CONTROL  
VALVE/THERMOSTAT  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
45  
16. After confirming no material of any type are  
between door gasket and combustion chamber  
shield, align the screws on the inner door with  
the screw holes on the combustion chamber and  
tighten with 1/4” nut driver or 1/4” socket & ratchet  
(Figure 97). After tightening the inner door  
screws, visually inspect area around door  
gasket and skirt for spaces or gaps. The door  
gasket MUST be sealed completely in order  
for the water heater to perform properly.  
DO NOT OPERATE THE WATER HEATER IF  
THE DOOR GASKET DOES NOT CREATE  
A SEAL BETWEEN MANIFOLD DOOR AND  
COMBUSTION CHAMBER.  
Figure 101.  
PRESSURE  
SWITCH  
MANIFOLD  
TUBE  
17. Reconnect the manifold tube to the gas control valve/  
thermostat (Note: Do Not apply any thread sealant  
at this connection). To prevent any cross threading  
the manifold tube should be started by hand (turn  
clockwise -natural gas). Upon tightening with the  
fingers and confirming it has not been cross threaded,  
tighten nut with an 3/4” open end wrench or crescent  
wrench (Figure 100).  
18. Reconnect all the electrical connections to the bottom  
of the gas control valve/thermostat, gently pushing  
each connector up snapping into place (Figure 100).  
19. Reconnect the electrical flag terminals and air  
pressure tubing to pressure switch (Figure 101).  
20. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from the  
transformer to the electric outlet (Figure 94).  
21. Restart the water heater by following the directions on  
the “Lighting and Operating Instructions” label located  
on the front of the water heater.  
22. As the burner is heating (view flames through  
viewport), test the manifold tube connection at the gas  
control valve/thermostat by brushing on an approved  
noncorrosive leak detection solution (IMPORTANT:  
Do Not splash any solution onto any electrical  
connections) (Figure 100).  
23. Upon verifying proper operation of the water heater,  
replace the manifold cover/outer door.  
46  
BURNER ORIFICE REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 102.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: 3/4” Open-End Wrench or Crescent  
Wrench, Phillips Head Screwdriver, Ratchet with 1/4”  
socket or 1/4” Nut Driver, Ratchet with 1/2” socket.  
HOTTER  
COOLER  
Electronic Control Display  
Removing the Inner Door/Manifold/Burner Assembly:  
Figure 103.  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 102).  
ON  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 103).  
OFF  
ON/OFF  
SWITCH  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 103).  
4. Remove the manifold cover/outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
UNPLUGGED  
5. Unplug all the electrical connections from the  
bottom of the gas control valve/thermostat  
(Figure 104).  
Figure 104.  
6. Disconnect the electrical flag terminals and  
air pressure tubing to the pressure switch  
(Figure 105).  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
7. Using a 3/4” open end wrench or a crescent  
wrench remove the manifold tube from the gas  
control valve/thermostat (turning counterclockwise  
-natural gas). Grasp the manifold tube and push  
down slightly to free the manifold tube from the  
gas control valve/thermostat (Figure 104).  
GAS CONTROL  
VALVE/THERMOSTAT  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
8. Use a 1/4” nut driver or 1/4” socket & ratchet to  
loosen the 2 hex head screws on the inner door  
so the inner door/manifold/burner assembly can  
be removed (Figure 106).  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
Figure 105.  
9. Remove inner door/manifold/burner assembly by  
grasping the manifold and pulling straight back.  
Care should be taken when inner door and burner  
assembly passes through jacket opening that it  
does not damage any of the electrical wiring or  
the air pressure hose (Figure 107).  
PRESSURE  
SWITCH  
MANIFOLD  
TUBE  
47  
Removing Old Burner Orifice :  
Figure 106.  
11. Burner may be hot, wait until burner has cooled  
off. After noting the position of the condensation  
drain hole on the top of the burner. Turn the inner  
door/manifold/burner assembly upside. Using a  
phillips head screwdriver remove the 2 screws  
attaching the burner to the manifold pipe (saving  
screws for reinstallation later) (Figure 108).  
1/4” HEX  
HEAD SCREW  
12. Using a ratchet with 1/2” socket, remove the  
burner’s old orifice (Note: the burner orifices have  
different threads dependent upon the gas type.  
Right handed treads for natural gas (Figure 109).  
Installing New Burner Orifice :  
Figure 107.  
13. Using a ratchet with 1/2” socket, install the  
new burner orifice (Note: the burner orifices  
have different threads dependent upon the gas  
type. Right handed treads for natural gas (turn  
clockwise to install) and Left handed threads for  
propane gas (turn counterclockwise to install)  
(Figure 109).  
INNER DOOR/  
MANIFOLD/BURNER  
ASSEMBLY  
SLOT  
14. Care MUST be taken to ensure the burner is  
installed correctly on the inner door/manifold  
assembly. Position the new burner upside down  
with the orientation of the burner’s condensation  
drain as shown in illustration (Figure 108).  
BURNER’S  
TIP END  
TAB  
15. Align the screw holes on the inner door/manifold  
assembly. Using the two screws removed in step  
11, installed the new burner to the inner door/  
manifold assembly (rotate the assembly to visually  
check the top portion of the burner assembly and  
confirm the orientation of the condensation drain  
hole on the top of the burner is toward the back as  
shown in the illustration) (Figure 108).  
Figure 108.  
BURNER’S  
CONDENSATION DRAIN  
TOP VIEW  
ORIENTATION OF SCOOP  
TO BE ON THE SAME SIDE  
AS THE VIEW PORT  
Installation Caution Must Be Taken:  
VIEW PORT  
16. Prior to installing the new inner door/manifold/  
burner assembly, look inside the burner chamber  
to fully understand the correct positioning of the  
burner assembly and burner manifold tab (Figure  
107). It may be necessary to use a flashlight  
to ensure correct placement. Care must be  
taken so as to not damage any electrical wiring,  
components or the air pressure tubing as you  
are installing the new inner door/manifold/burner  
assembly.  
TWO SCREWS  
BURNER’S  
CONDENSATION DRAIN  
BOTTOM VIEW  
Figure 109.  
Extra caution should be taken to ensure  
that electrical wiring, air hose, fiberglass  
insulation nor any other object is between  
door gasket and combustion chamber shield.  
BURNER  
ORIFICE  
SCREWS  
48  
Reinstalling The Inner Door/Manifold/Burner Assembly  
Figure 110.  
17. Insert the manifold/burner assembly in the burner  
chamber compartment, making sure that the tip  
of burner manifold tab engages in the slot of the  
bracket (Figure 107).  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
The tip end of the burner manifold MUST  
be placed in the slotted portion under the  
condensation pan to obtain proper installation  
(Figure 107).  
GAS CONTROL  
VALVE/THERMOSTAT  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
18. After confirming no material of any type are  
between door gasket and combustion chamber  
shield, align the screws on the inner door with  
the screw holes on the combustion chamber and  
tighten with 1/4” nut driver or 1/4” socket & ratchet  
(Figure 106). After tightening the inner door  
screws, visually inspect area around door  
gasket and skirt for spaces or gaps. The door  
gasket MUST be sealed completely in order  
for the water heater to perform properly.  
DO NOT OPERATE THE WATER HEATER IF  
THE DOOR GASKET DOES NOT CREATE  
A SEAL BETWEEN MANIFOLD DOOR AND  
COMBUSTION CHAMBER.  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
Figure 111.  
PRESSURE  
SWITCH  
19. Reconnect the manifold tube to the gas control  
valve/thermostat (Note: Do Not apply any thread  
sealant at this connection). To prevent any cross  
threading the manifold tube should be started  
by hand (turn clockwise -natural gas). Upon  
tightening with the fingers and confirming it has  
not been cross threaded, tighten nut with an 3/4”  
open end wrench or crescent wrench (Figure 110).  
MANIFOLD  
TUBE  
20. Reconnect all the electrical connections to the  
bottom of the gas control valve/thermostat, gently  
pushing each connector up snapping into place  
(Figure 110).  
21. Reconnect the electrical flag terminals and air  
pressure tubing to pressure switch (Figure 111).  
22. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 103).  
23. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater.  
24. As the burner is heating (view flames through  
viewport), test the manifold tube connection at  
the gas control valve/thermostat by brushing on  
an approved noncorrosive leak detection solution  
(IMPORTANT: Do Not splash any solution onto  
any electrical connections) (Figure 110).  
25. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
49  
GAS CONTROL VALVE/THERMOSTAT REMOVAL / REPLACEMENT  
Important: Use only factory authorized replacement  
Figure 112.  
parts. If you lack the necessary skills to properly  
perform the installation, you should not proceed, but  
get help from a qualified service technician.  
Tools required: 3/4” Open-End Wrench or Crescent  
Wrench, Phillips Head Screwdriver, a short length of  
1/2” threaded Pipe.  
HOTTER  
COOLER  
Removing the Gas Control Valve/Thermostat:  
Electronic Control Display  
1. Set the gas control valve/thermostat to its lowest  
setting by pressing the “COOLER” and “HOTTER”  
buttons together at the same time holding for 1  
second. Then press the “COOLER” button to the  
lowest setting (Figure 112).  
Figure 113.  
ON  
2. Turn gas control switch to the “OFF” position  
(located right side of the gas control valve/  
thermostat) and turn off the gas supply to the unit  
(Figure 113).  
OFF  
3. Disconnect the electric connection by unplugging  
the transformer from the wall outlet (Figure 113).  
ON/OFF  
SWITCH  
4. Release water pressure by opening a nearby hot  
water faucet, let run until water is cool to touch.  
Turn off water supply to the water heater.  
5. Remove the manifold cover/ outer door from the  
unit by depressing on the lower portion and pulling  
outward.  
UNPLUGGED  
6. Connect a drain hose to the drain valve and run  
it to an adequate drain or to the exterior of the  
building. Open the water heater drain valve and  
allow the water to drain from the tank.  
Figure 114.  
7. Unplug all the electrical connections from the  
bottom of the gas control valve/thermostat  
(Figure 114).  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
GAS CONTROL  
VALVE/THERMOSTAT  
8. Using a 3/4” open end wrench or a crescent  
wrench remove the manifold tube from the gas  
control valve/thermostat (turning counterclockwise  
-natural gas). Grasp the manifold tube and push  
down slightly to free the manifold tube from the  
gas control valve/thermostat (Figure 114).  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
9. Using a phillips head screwdriver remove the  
transformer box from the front of the water heater  
by removing the one (1) screw at the top of the  
transformer box (save screw for reinstallation  
later) (Figure 115).  
Figure 115.  
10. Disconnect the two (2) electrical flag connectors  
from the pressure switch, also disconnect the air  
pressure tubing. Using a phillips head screwdriver  
remove the pressure switch from the water  
heater’s front by removing the two (2) screws  
securing it (save screws for reinstallation later)  
(Figure 115).  
PRESSURE  
SWITCH  
MANIFOLD  
TUBE  
SCREW AT  
TRANSFORMER  
BOX  
50  
11. Ensuring that the gas supply line is turned off,  
disconnect the gas piping at the ground joint union,  
then remove the gas piping from the gas control valve/  
thermostat (Figure 116).  
Figure 116.  
GAS SHUT-OFF  
12. Remove any other fittings that may be installed on  
the threaded pipe to the gas control valve/thermostat  
(Figure 116).  
GROUND JOINT UNION  
13. After ensuring the water heater is completely drained,  
thread a short length of 1/2” threaded pipe into the  
inlet connection of the gas control valve/thermostat  
and use it to turn the gas control valve/thermostat  
counterclockwise to remove (Figure 117).  
GAS PIPING  
ROTATE TO:  
Installing the Gas Control Valve/Thermostat:  
Figure 117.  
GAS CONTROL VALVE /  
THERMOSTAT  
ROTATE TO:  
14. Before installing, apply Teflon® tape or an approved  
pipe sealant on the threads of the new gas control  
valve/thermostat (only the threads that screw into  
tank).  
INSTALL  
REMOVE  
15. Thread a short length of 1/2” threaded pipe into  
the inlet connection of the new gas control valve/  
thermostat and use it to turn the gas control valve/  
thermostat clockwise to tighten into place (Note: Do  
Not over tighten or damage may result, but it needs to  
be water tight (Min. 35 foot pounds) (Figure 117).  
SHORT LENGTH OF  
1/2” TREADED PIPE  
16. Remove the 1/2” threaded pipe from the gas control  
valve/thermostat.  
17. Reconnect the gas piping to the gas control valve/  
thermostat, use Teflon® tape or an approved pipe  
sealant on threads of the piping (Figure 116).  
Figure 118.  
18. Close the drain valve and turn on the cold water supply  
line filling the tank completely with water. Purge the  
water lines of any excess air by opening a hot water  
faucet allowing the water to flow for a minimum of 3  
minutes, allowing the tank to fill completely.  
PRESSURE  
SWITCH  
19. Using the two (2) phillips head screws removed earlier  
in step 10, reattach the air pressure switch (orientation  
with pressure tubing connector to the down side) to the  
front of the water heater. Reattach the electrical flag  
terminal to the pressure switch. Reattach the pressure  
tubing (Figure 118).  
MANIFOLD  
TUBE  
SCREW AT  
TRANSFORMER  
BOX  
20. Reinstall the transformer box to the front of the  
water heater by using the one (1) phillips head screw  
removed earlier in step 9 (Figure 118).  
Figure 119.  
21. Reconnect the manifold tube to the gas control valve/  
thermostat (Note: Do Not apply any thread sealant  
at this connection). To prevent any cross threading  
the manifold tube should be started by hand (turn  
clockwise -natural gas). Upon tightening with the  
fingers and confirming it has not been cross threaded,  
tighten nut with an 3/4” open end wrench or crescent  
wrench (Figure 119).  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
GAS CONTROL  
VALVE/THERMOSTAT  
PRESSURE  
22. Reconnect all the electrical connections to the bottom  
of the gas control valve/thermostat, gently pushing  
each connector up snapping into place (Figure 119).  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
Teflon® is a registered trademark of E.I. Du Pont De Numours and Company.  
51  
23. Turn on the gas supply to the unit and test the gas  
supply line and union connections by brushing on  
an approved noncorrosive leak detection solution  
(Figure 116).  
Figure 120.  
24. Turn on the electrical and the gas supplies to the  
water heater. Plug in the electric connection from  
the transformer to the electric outlet (Figure 113).  
IMPORTANT:  
WHEN BRUSHING ON AN  
APPROVED NONCORROSIVE  
LEAK DETECTION SOLUTION,  
DO NOT SPLASH SOLUTION  
ONTO ELECTRICAL CON-  
NECTIONS.  
GAS CONTROL  
VALVE/THERMOSTAT  
25. Restart the water heater by following the  
directions on the “Lighting and Operating  
Instructions” label located on the front of the water  
heater .  
PRESSURE  
SWITCH/FAN,  
FV SENSOR  
CONNECTOR  
MANIFOLD TUBE  
POWER SUPPLY  
TRANSFORMER  
CONNECTOR  
IGNITER/  
FLAME  
SENSE  
26. As the burner is heating (view flames through  
viewport), test the manifold tube connection at  
the gas control valve/thermostat by brushing on  
an approved noncorrosive leak detection solution  
(IMPORTANT: Do Not splash any solution onto  
any electrical connections) (Figure 120).  
DISPLAY, ANODE  
ROD CONNECTOR  
CONNECTOR  
27. Upon verifying proper operation of the water  
heater, replace the manifold cover/outer door.  
CHECKING THE GAS SUPPLY PRESSURE  
Checking the Gas Supply Pressure  
Gas pressure checks are done with flowing gas  
using a gas pressure gauge capable of reading  
pressure in inches of water column.  
GAS CONTROL  
VALVE/  
THERMOSTAT  
GAS CONTROL  
VALVE/  
THERMOSTAT  
Supply gas pressure checks are measured  
before the gas control valve/thermostat and  
as close to the water heater as possible.  
USE AN ALLEN  
WRENCH TO REMOVE  
AND REPLACE PLUG.  
Manifold (main burner) gas pressure is  
measured at the pressure tap on the side  
of the gas control valve/thermostat. Use  
an allen wrench to remove the plug then  
attach the gas gauge.  
GAS  
PRESSURE  
GAUGE  
MANIFOLD GAS PRESSURE TEST  
CONNECTED AT  
PRESSURE TAP  
SUPPLY GAS PRESSURE TEST  
Figure 121  
NOTE: Desired gas pressures will be noted on  
the gas valve label located on the gas control  
valve/thermostat.  
IF . . .  
. . . THEN  
supply gas pressure is under desired pressure  
requirement  
increase supply gas pressure regulator setting  
and,  
increase supply gas piping size.  
supply gas pressure is over desired pressure  
add gas pressure regulator.  
reduce setting on existing regulator.  
ensure there is adequate supply gas pressure  
manifold gas pressure is more than +/- .3 inch  
W.C. from values indicated on gas valve  
ensure the main burner orice is the correct size  
for the water heater model being tested.  
if the above tests have been performed and the  
results were correct replace the gas control valve.  
52  
GAS WATER HEATER SIZING GUIDE  
Use the following information as a guide to approximate the correct size water heater for the residence:  
40 gallon size (28 gallon draw) for two bath residence -or one bath with an automatic clothes washer.  
50 gallon size (35 gallon draw) for three bath residence - or two baths with an automatic clothes  
washer.  
When a whirlpool tub is part of the home equipment, it is suggested that the water heater storage  
tank capacity be selected based on the needs of the whirlpool tub. This method of tank sizing, will in  
most cases, cancel all statements above concerning tank sizing.  
High ow or multiple shower head installations must be sized for at least a 20 minute draw.  
Table 2:  
Tub Capacity to Overow  
Outlet at:  
80 gal.  
80 gal.  
65 gal.  
54 gal.  
90 gal.  
90 gal.  
71 gal.  
59 gal.  
100 gal.  
100 gal.  
80 gal.  
66 gal.  
110 gal.  
110 gal.  
89 gal.  
74 gal.  
120 gal.  
120 gal.  
98 gal.  
82 gal.  
130 gal.  
130 gal.  
108 gal.  
90 gal.  
140 gal.  
140 gal.  
117 gal.  
97 gal.  
150 gal.  
150 gal.  
125 gal.  
104 gal.  
(120ºF Water) Min. Stored  
Water Capacity**  
(140ºF Water*) Min. Stored  
Water Capacity**  
(@ 160ºF Water*) Min.  
Stored Water Capacity**  
*A thermostatic mixing valve set for a maximum temperature of 120° F is recommended to be installed to prevent a scalding hazard.  
**Based on tub water temperature of 105º  
Note: Because the desired ll time is normally 10 minutes, recovery capacity is not used for this calculation. All water used is supplied  
by storage.  
NOTE: The draw efciency of a gas or electric water heater storage tank is considered to be 70%.  
LEAKAGE CHECKPOINTS  
A. Water at the draft hood is water vapor which has  
condensed out of the combustion products. This is  
caused by a problem in the vent.  
B. *Condensation may be seen on pipes in humid  
weather or pipe connections may be leaking.  
C. *The powered anode rod tting may be leaking.  
D. Small amounts of water from temperature-pressure  
relief valve may be due to thermal expansion or  
high water pressure in your area.  
*
To check where threaded portion enters tank,  
insert cotton swab between jacket opening and  
tting. If cotton is wet, follow draining instructions  
in the “Draining the Water Heater” section and then  
remove tting. Put pipe dope or Teon® tape on the  
threads and replace. When you are nished, follow  
the steps in “Filling the Water Heater” section.  
A
C
B
E. *The temperature-pressure relief valve may be  
leaking at the tank tting.  
F. Water from a drain valve may be due to the valve  
being slightly opened.  
E
G. *The drain valve may be leaking at the tank tting.  
H. Combustion products contain water vapor which  
can condense on the cooler surfaces of the tank.  
Droplets form and drip onto the burner or run on  
the oor. This is common at the time of start-up  
after installation and when incoming water is cold.  
I. Water in the water heater bottom or on the oor  
may be from condensation, loose connections, or  
the relief valve. DO NOT replace the water heater  
until a full inspection of all possible water sources  
is made and necessary corrective steps taken.  
D
G
H
F
I
6” (152.4 mm)  
MAXIMUM AIR GAP  
Leakage from other appliances, water lines, or ground  
seepage should also be checked.  
Figure 122  
53  
GENERAL INFORMATION  
Draw efficiency is the quantity of hot water available to the consumer before the outlet water temperature decreases  
25 degrees F. A 40 gallon water heater will typically provide 70% (28 gallons) of this “usable” hot water (60% is the  
minimum). The burner or elements are allowed to operate during this test. Incoming, cold water mixes the remaining  
stored water below this 25 degree limitation.  
Energy Factor is an indicator of the combined thermal efficiency and standby efficiency of a water heater. The higher the  
energy factor, the more efficient the water heater will be.  
Minerals and gases will separate from water as temperature increases.  
“R” Value is a measure of the resistance of a substance to heat flow.  
Recovery rate is the amount of water that is heated to a set temperature, per hour. An example might be that a water  
heater has a recovery rate of 30 gallons of water per hour at 80 degree F. (Fahrenheit) temperature rise.  
Standby efficiency – the water heater’s ability to contain heat in the tank. A minimum of tank water heat loss per hour  
is desired.  
Sample: temperature change  
“R” value  
= Btu/h loss/ square foot of tank surface  
Temperature rise is the increase in the temperature from its coldest “inlet” water temperature to the desired hot (outlet)  
setting. Typically this is assumed to be 40 degrees entering water, 120 degrees desired stored water or 80 degrees  
“temperature rise.”  
Thermal efficiency is approximately the amount of generated BTU (British Thermal Units), which enters the water. A  
percentage of the total BTU passes out through the vent piping.  
Water cannot (for all practical purposes) be compressed.  
Water expands when it is heated.  
Formulas and Conversions:  
BTU (British Thermal Unit) is the heat required to raise 1 pound of water 1°F  
1 BTU = 252 cal = 0.252 kcal  
1 cal = 4.187 Joules  
BTU X 1.055 = Kilo Joules  
BTU divided by 3,413 = Kilowatts  
To convert from Fahrenheit to Centigrade: (° F – 32) times 5/9, or .556, equals degrees C.  
One gallon of (120 ° F, 49 ° C) water weighs approximately 8.25 pounds.  
Pounds X .45359 = Kilogram  
Gallons X 3.7854 = Liters  
% of Hot = (Mixed Temp. – Cold) divided by (Hot Temp. – Cold)  
% Thermal Efficiency = (GPH X 8.25 X Temp. Rise X 1.0) divided by BTU/H Input  
BTU Output = GPH X 8.25 X Temp. Rise X 1.0  
GPH = (BTU/H Input X % Eff.) divided by (Temp. Rise X 8.25)  
One cubic foot of Natural Gas contains about 1000 BTU of heat.  
One “therm” is equal to 100,000 BTU  
One cubic foot of Propane Gas contains about 2500 BTU of heat.  
One gallon of Propane gas contains about 91,250 BTU of heat.  
One pound of Propane gas contains about 21,600 BTU of heat.  
54  
GENERAL INFORMATION  
One pound of gas pressure is equal to 27.7 inches water column pressure  
Inches of Water Column X .036091 = PSI  
Inches of Water Column X .073483 = Inches of Mercury (Hg.)  
Centimeters = Inches X 2.54  
MM (millimeters) =Inches X 25.4  
Meters = Inches X .0254  
Doubling the diameter of a pipe will increase its flow capacity (approximately) 5.3 times.  
Construction: Tank is constructed of steel.  
The inside of the tank is constructed of a glass lining bonded to the steel. This prevents water to metal contact and  
rusting of the tank.  
An anode rod will be installed within the tank. The hex-head plug end of the anode is visible on the top of the water  
heater. This metal rod offers secondary protection of the tank against corrosion where the application of glass is not  
possible (threaded tank openings). These areas will have small areas of water to metal contact.  
All water heaters will contain at least one thermostat (to operate the heater) and one high limit (to prevent water  
temperatures approaching the “steam” level).  
55  
ALL TECHNICAL AND WARRANTY QUESTIONS SHOULD BE DIRECTED TO THE LOCAL DEALER FROM WHOM THE WATER HEATER WAS PURCHASED. IF  
YOU ARE UNSUCCESSFUL, CONTACTA O SMITH WATER HEATERS RESIDENTIAL TECHNICALASSISTANCE AT 1-800-527-1953 OR WWW.HOTWATER.COM.  
56  

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