AO Smith Electric Heater WATER HEATERS User Guide

Instruction Manual  
RESIDENTIAL ELECTRIC  
WATER HEATERS  
ATER  
ONLY  
E FOR  
ATING  
LISTED  
GAMA certification applies to all  
residential electric water heaters  
with capacities of 20 to 120 gallons.  
Input rating of 12 Kw or less.  
ALLTECHNICALAND WARRANTY QUESTIONS: SHOULD BE DIRECTEDTOTHE LOCALDEALER FROM WHOM THE WATER HEATER WAS  
PURCHASED.IFYOUAREUNSUCCESSFUL,PLEASEWRITETOTHECOMPANYLISTEDONTHERATINGPLATEONTHEWATERHEATER.  
KEEPTHIS MANUALIN THE POCKET ON HEATER FOR FUTURE REFERENCE  
WHEN EVER MAINTENANCE ADJUSTMENT OR SERVICE IS REQUIRED.  
PRINTED IN THE U.S.A 1203  
PART NO. 184639-000  
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SAFE INSTALLATION, USE AND SERVICE  
Your safety and the safety of others is extremely important in the installation, use and servicing of this water heater.  
Many safety-related messages and instructions have been provided in this manual and on your own water heater to warn you and  
others of a potential injury hazard. Read and obey all safety messages and instructions throughout this manual. It is very  
important that the meaning of each safety message is understood by you and others who install, use or service this water heater.  
This is the safety alert symbol. It is used to alert you  
to potential personal injury hazards. Obey all safety  
messages that follow this symbol to avoid possible  
injury or death.  
DANGER indicates an imminently  
DANGER  
WARNING  
hazardous situation which, if not avoided,  
could result in death or injury.  
WARNING indicates a potentially hazardous  
situation which, if not avoided, could result  
in death or injury.  
CAUTION indicates a potentially hazardous  
situation which, if not avoided, may result  
in minor or moderate injury.  
CAUTION  
CAUTION  
CAUTION used without the safety alert  
symbol indicates a potentially hazardous  
situation which, if not avoided, could result  
in property damage.  
All safety messages will generally tell you about the type of hazard, what can happen if you do not follow the safety message and  
how to avoid the risk of injury.  
IMPORTANT DEFINITIONS  
Qualified Installer: A qualified installer must have ability equivalent to a licensed tradesman in the fields of plumbing, and electrical installation  
of these appliances. This would include a thorough understanding of the requirements of the National Electrical Code and applicable local  
electrical and plumbing codes (and tools necessary to confirm proper installation and operation of the water heater) as they relate to  
the installation of electric water heaters. The qualified installer must have a thorough understanding of the water heater  
Instruction Manual.  
Service Agency: A service agency also must have ability equivalent to a licensed tradesman in the fields of plumbing, and electrical installation  
of these appliances. This would include a thorough understanding of the requirements of the National Electrical Code and applicable local  
electrical and plumbing codes (and tools necessary to confirm proper installation and operation of the water heater) as they relate to  
the installation of electric water heaters. The service agency must have a thorough understanding of the water heater  
Instruction Manual.  
2
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GENERAL SAFETY  
TABLE OF CONTENTS  
SAFE INSTALLATION, USEAND SERVICE .............................. 2  
TemperatureAdjustment ................................................ 11  
FORYOUR INFORMATION ..................................................... 12  
Thermal Expansion ......................................................... 12  
Strange Sounds ............................................................. 12  
Operational Conditions ................................................... 12  
Smelly Water .................................................................. 12  
“Air” in Hot Water Faucets............................................. 12  
High Water Temperature Shut Off System .................... 12  
PERIODICMAINTENANCE ....................................................... 12  
Anode Rod Inspection .............................................. 12-13  
Temperature-Pressure Relief Valve Operation .............. 13  
Draining .......................................................................... 13  
Drain Valve Washer Replacement ................................. 13  
Service ........................................................................... 13  
LEAKAGECHECKPOINTS ...................................................... 14  
REPAIR PARTS LIST ............................................................... 15  
TROUBLESHOOTING .............................................................. 16  
WARRANTY ..................................................................... Insert  
GENERAL SAFETY .................................................................. 3  
TABLE OF CONTENTS .............................................................. 3  
INTRODUCTION ........................................................................ 4  
Preparing for the New Installation ................................... 4  
NOTES ...................................................................................... 4  
TYPICALINSTALLATION .......................................................... 5  
WIRINGDIAGRAMS .................................................................. 6  
MIXING VALVE USAGE ............................................................ 7  
LOCATINGTHE NEW WATER HEATER ..................................... 8  
Facts to Consider About Location ................................... 8  
Insulation Blankets ........................................................... 8  
INSTALLING THE NEW WATER HEATER .................................. 8  
Water Piping ................................................................. 8-9  
Temperature-Pressure Relief Valve........................... 9-10  
Filling the Water Heater .................................................. 10  
T&P Valve and Pipe Insulation (Selected Models) ......... 10  
TEMPERATUREREGULATION ................................................ 11  
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INTRODUCTION  
Thank You for purchasing this water heater. Properly installed and  
maintained, it should give you years of trouble free service.  
2. The installation must conform with these instructions and the local  
code authority having jurisdiction and the requirements of the power  
company. In the absence of code requirements follow NFPA-70  
(latest edition). The National Electric Code which may be ordered  
from: National Fire Protection Association, 1 Batterymarch Park,  
Quincy, MA02269.  
Abbreviations Found In This Instruction Manual:  
ANSI -American National Standards Institute  
ASME -American Society of Mechanical Engineers  
GAMA- GasAppliance Manufacturer’sAssociation  
NEC - National Electric Code  
3. If after reading this manual you have any questions or do not  
understand any portion of the instructions, call the local utility or the  
manufacturer whose name appears on the rating plate.  
NFPA- National Fire ProtectionAssociation  
UL - Underwriters Laboratory  
4. Carefully plan the place where you are going to put the water heater.  
INSTALLATIONORSERVICEOFTHISWATERHEATERREQUIRES  
ABILITYEQUIVALENTTOTHATOFALICENSEDTRADESMAN IN  
THE FIELD INVOLVED. PLUMBINGAND ELECTRICALWORKARE  
REQUIRED.  
PREPARING FOR THE INSTALLATION  
1. Read the “General Safety” section of this manual first and then the  
entire manual carefully. If you don’t follow the safety rules, the  
water heater will not operate properly. It could cause DEATH,  
SERIOUSBODILYINJURYAND/ORPROPERTYDAMAGE.  
Examine the location to ensure the water heater complies with the  
“Facts to ConsiderAbout the Location” section in this manual.  
5. For California installation this water heater must be braced, anchored,  
or strapped to avoid falling or moving during an earthquake. See  
instructions for correct installation procedures. Instructions may be  
obtained from California Office of the StateArchitect, 400 P Street,  
Sacramento, CA 95814.  
This manual contains instructions for the installation, operation, and  
maintenance of the electric water heater. It also contains warnings  
throughout the manual that you must read and be aware of. All  
warnings and all instructions are essential to the proper operation of  
the water heater and your safety. Since we cannot put everything  
on the first few pages, READ THE ENTIRE MANUAL BEFORE  
ATTEMPTING TO INSTALL OROPERATE THE WATER HEATER.  
6. Massachusetts Code requires this water heater to be installed in  
accordance with Massachusetts 248-CMR 2.00: State Plumbing Code  
and 248-CMR 5.00.  
NOTES  
4
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TYPICAL INSTALLATION  
LOWBOYS  
UPRIGHTS  
COMPACTS  
TABLE TOPS  
INSTALL SUITABLE DRAIN PANS UNDER HEATERS  
TO PREVENT DAMAGE DUE TO LEAKAGE. REFER  
TO WATER HEATER LOCATION ON PAGE 8.  
INSTALL VACUUM RELIEF IN COLD WATER  
INLET LINE AS REQUIRED BY LOCAL CODES.  
INSTALL THERMAL EXPANSION TANK OR DEVICE  
IF WATER HEATER IS INSTALLED IN A CLOSED  
WATER SYSTEM.  
FIGURE1.  
5
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WIRING DIAGRAMS  
TURN OFF THE HEATER ELECTRICAL SUPPLY BEFORE SERVICING ANY ELECTRICAL COMPONENTS.  
C-2  
A-9  
TWO WIRE CIRCUIT FOR SINGLE  
ELEMENTHEATERSEQUIPPED  
WITH HIGH LIMIT CONTROL  
240 VOLT “OFF PEAK” NON-SIMULTANEOUS  
OPERATION BOTTOM ELEMENT ON SEPARATE  
TIME CLOCK OR “OFF PEAK” METER  
S-1  
THREE WIRE CIRCUIT FOR  
ELECTRIC CO. CO-OP  
PROGRAMS  
A-6  
TWO WIRE CIRCUIT FOR  
NON-SIMULTANEOUS OPERATION
HAS SINGLE HIGH LIMIT CONTROL  
FIGURE2.  
6
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MIXING VALVE USAGE  
FIGURE3.  
Water (Potable) Heating: All models are considered suitable for  
water (potable) heating only.  
HOTTERWATERCANSCALD:  
Water heaters are intended to produce hot water. Water heated to a  
temperature which will satisfy space heating, clothes washing, dish  
washing, and other sanitizing needs can scald and permanently injure  
you upon contact. Some people are more likely to be permanently  
injured by hot water than others. These include the elderly, children, the  
infirm, or physically/mentally handicapped. If anyone using hot water in  
your home fits into one of these groups or if there is a local code or state  
law requiring a certain temperature water at the hot water tap, then you  
must take special precautions. In addition to using the lowest possible  
temperature setting that satisfies your hot water needs, a means such  
as a *mixing valve, shall be used at the hot water taps used by these  
people or at the water heater. Mixing valves are available local plumbing  
contractor. Consult a Qualified Installer or Service Agency. Follow  
mixing valve manufacturer’s instructions for installation of the valves.  
Before changing the factory setting on the thermostat, read the  
Temperature Regulation” section in this manual.  
7
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LOCATING THE NEW WATER HEATER  
damage to the structure. For this reason, it is not advisable to install the  
FACTS TO CONSIDERABOUT THE LOCATION  
water heater in an attic or upper floor. When such locations cannot be  
avoided, a suitable drain pan should be installed under the water heater.  
Drain pans are available from your local plumbing contractor. Such a  
drain pan must have a minimum length and width of at least 2 inches  
(51 mm) greater that the water heater dimensions and must be piped to  
an adequate drain.  
Also, the water heater must be located and/or protected so it is not  
subject to physical damage by a moving vehicle.  
INSULATION BLANKETS  
Carefully choose an indoor location for the new water heater, because  
the placement is a very important consideration for the safety of the  
occupants in the building and for the most economical use of the  
appliance.  
Insulation blankets are available to the general public for external use  
on electric water heaters but are not necessary with this product. The  
purpose of an insulation blanket is to reduce the standby heat loss  
encountered with storage tank heaters. Your water heater meets or  
exceeds the National Appliance Energy ConversationAct standards  
with respect to insulation and standby loss requirements, making an  
insulation blanket unnecessary.  
Whether replacing an old water heater or putting the water heater in a  
new location, the following critical points must be observed:  
Should you choose to apply an insulation blanket to this heater, you  
should follow these instructions below. Failure to follow these  
instructions can result in fire, serious personal injury, or death.  
1. Select a location indoors as close as practical or centralized to the  
water piping system as possible. The water heater should be  
located in an area not subject to freezing temperatures.  
Do not cover the temperature and pressure relief (T & P) valve with  
an insulation blanket.  
2. Selected location must provide adequate clearances (4”) for servicing  
parts such as the thermostats, drain valve and relief valve. Adequate  
clearance for servicing this appliance should be considered before  
installation, such as changing the anodes, etc.  
Do not cover the instruction manual. Keep it on the side of the  
water heater or nearby for future reference.  
Installation of the water heater must be accomplished in such a manner  
that if the tank or any connections should leak, the flow will not cause  
Do obtain new warning and instruction labels for placement on the  
blanket directly over the existing labels.  
INSTALLING THE NEW WATER HEATER  
taps used by these people or at the water heater. Valves for reducing  
WATER PIPING  
point of use temperature by mixing cold and hot water are also available.  
Consult a Qualified Installer or ServiceAgency. Follow manufacturer’s  
instructions for installation of the valves. Before changing the factory  
setting on the thermostat, read the “Temperature Regulation” section in  
this manual.  
This water heater shall not be connected to any heating systems or  
component(s) used with a non-potable water heating appliance.  
HOTTER WATER CAN SCALD:  
Water heaters are intended to produce hot water. Water heated to a  
temperature which will satisfy space heating, clothes washing, dish  
washing, cleaning and other sanitizing needs can scald and permanently  
injure you upon contact. Some people are more likely to be permanently  
injured by hot water than others. These include the elderly, children,  
the infirm, or physically/mentally handicapped. If anyone using hot  
water in your home fits into one of these groups or if there is a local  
code or state law requiring a certain temperature water at the hot  
water tap, then you must take special precautions. In addition to using  
the lowest possible temperature setting that satisfies your hot water  
needs, a means such as a *mixing valve, shall be used at the hot water  
Toxic chemicals, such as those used for boiler treatment shall not be  
introduced into this system.  
Water supply systems may, because of such events as high line  
pressure, frequent cut-offs, the effects of water hammer among  
others, have installed devices such as pressure reducing valves, check  
valves, back flow preventers, etc. to control these types of problems.  
When these devices are not equipped with an internal by-pass, and no  
other measures are taken, the devices cause the water system to be  
closed. As water is heated, it expands (thermal expansion) and closed  
systems do not allow for the expansion of heated water.  
8
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The water within the water heater tank expands as it is heated and  
increases the pressure of the water system. If the relieving point of  
the water heater’s temperature-pressure relief valve is reached, the  
valve will relieve the excess pressure. The temperature-pressure  
relief valve is not intended for the constant relief of thermal  
expansion. This is an unacceptable condition and must be corrected.  
It is recommended that any devices installed which could create a  
closed system have a by-pass and/or the system have an expansion  
tank or device to relieve the pressure built by thermal expansion in the  
water system. Expansion tanks are available for ordering through a  
local plumbing contractor. Contact the local water supplier and/or a  
service agency for assistance in controlling these situations.  
TEMPERATURE-PRESSURE RELIEF VALVE  
NOTE: To protect against untimely corrosion of hot and cold  
water fittings, it is strongly recommended that di-electric  
unions or couplings be installed on this water heater when  
connected to copper pipe.  
This heater is provided with a properly certified combination  
temperature - pressure relief valve by the manufacturer.  
The valve is certified by a nationally recognized testing laboratory that  
maintains periodic inspection of production of listed equipment of  
materials as meeting the requirements for Relief Valves andAutomatic  
Gas Shut-off Devices for Hot Water Supply Systems, ANSI Z21.22 •  
CSA4.4, and the code requirements ofASME.  
Figure 4 shows the typical attachment of the water piping to the water  
heater. The water heater is equipped with 3/4 inch NPT water  
connections.  
If replaced, the valve must meet the requirements of local codes, but  
not less than a combination temperature and pressure relief valve  
certified as indicated in the above paragraph.  
NOTE: If using copper tubing, solder tubing to an adapter  
before attaching the adapter to the cold water inlet connection.  
Do not solder the cold water supply line directly to the cold  
water inlet, it will harm the dip tube and damage the tank.  
The valve must be marked with a maximum set pressure not to exceed  
the marked hydrostatic working pressure of the water heater  
(150 psi = 1,035 kPa) and a discharge capacity not less than the water  
heater input rate as shown on the model rating plate.  
For safe operation of the water heater, the relief valve must not be  
removed from its designated opening nor plugged.  
The temperature-pressure relief valve must be installed directly into  
the fitting of the water heater designed for the relief valve. Position the  
valve downward and provide tubing so that any discharge will exit  
only within 6 inches (153 mm) above, or at any distance below the  
structural floor. Be certain that no contact is made with any live electrical  
part. The discharge opening must not be blocked or reduced in size  
under any circumstances. Excessive length, over 30 feet (9.14 m), or  
use of more than four elbows can cause restriction and reduce the  
discharge capacity of the valve.  
No valve or other obstruction is to be placed between the relief valve  
and the tank. Do not connect tubing directly to discharge drain unless  
a 6 inch air gap is provided. To prevent bodily injury, hazard to life, or  
property damage, the relief valve must be allowed to discharge water  
in quantities should circumstances demand. If the discharge pipe is not  
connected to a drain or other suitable means, the water flow may  
cause property damage.  
FIGURE4.  
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The Discharge Pipe:  
If after manually operating the valve, it fails to completely reset and  
continues to release water, immediately close the cold water inlet to  
the water heater, follow the draining instructions, and replace the  
temperature-pressure relief valve with a new one.  
• Shall not be smaller in size than the outlet pipe size of the valve, or  
have any reducing couplings or other restrictions.  
• Shall not be plugged or blocked.  
FILLING THE WATER HEATER  
• Shall be of material listed for hot water distribution.  
• Shall be installed so as to allow complete drainage of both the  
temperature-pressure relief valve, and the discharge pipe.  
• Shall terminate at an adequate drain.  
• Shall not have any valve between the relief valve and tank.  
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” electrical  
supply to the water heater.  
To fill the water heater with water:  
1. Close the water heater drain valve by turning the handle to the right  
(clockwise). The drain valve is on the lower front of the water  
heater.  
2. Open the cold water supply valve to the water heater.  
NOTE: The cold water supply valve must be left open when  
the water heater is in use.  
3. To insure complete filling of the tank, allow air to exit by opening the  
nearest hot water faucet. Allow water to run until a constant flow  
is obtained. This will let air out of the water heater and the piping.  
The temperature-pressure relief valve must be manually operated at  
least once a year. Caution should be taken to ensure that (1) no one is  
in front of or around the outlet of the temperature-pressure relief valve  
discharge line, and (2) the water manually discharged will not cause  
any bodily injury or property damage because the water may be  
extremely hot.  
4. Check all water piping and connections for leaks. Repair as needed.  
PIPE INSULATION  
FIGURE6.  
T&P VALVE and PIPE INSULATION (On Selected Models)  
Remove insulation for T&PValve and pipe connections from carton.  
Fit pipe insulation over the incoming cold water line and the hot water  
line. Make sure that the insulation is against the top cover of the heater.  
Fit T&P Valve insulation over valve. Make sure that the insulation does  
not interfere with the lever or outlet of the T&P valve.  
Secure all insulation using tape.  
FIGURE5.  
10  
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TEMPERATURE REGULATION  
KEEPINGTHETHERMOSTATSETTINGAT120°F WILLREDUCETHE  
Due to the nature of the typical water heater, the water temperature in  
RISKOFSCALDS.  
certain situations may vary up to 30°F (16.7 °C) higher or lower at the  
point of use such as, bathtubs, showers, sink, etc.  
Figure 7 shows the approximate time-to-burn relationship for normal  
adult skin. The thermostats on your water heater have a linear  
relationship between degrees of angular rotation and the corresponding  
change in temperature. Thus rotating the temperature adjustment  
indicator 30 angular degrees will result in a 10 degree Fahrenheit  
change in water temperature.  
Any water heater’s intended purpose is to heat water. Hot water is  
needed for cleansing, cleaning, and sanitizing (bodies, dishes, clothing).  
Untempered hot water can present a scald hazard. Depending on the  
time element, and the people involved (adults, children, elderly, infirm,  
etc.) scalding may occur at different temperatures.  
TEMPERATUREADJUSTMENT  
To change the temperature setting:  
HOTTER WATER CAN SCALD: Water heaters are intended to produce  
hot water. Water heated to a temperature which will satisfy space  
heating, clothes washing, dish washing, and other sanitizing needs  
can scald and permanently injure you upon contact. Some people are  
more likely to be permanently injured by hot water than others. These  
include the elderly, children, the infirm, or physically/mentally  
handicapped. If anyone using hot water in your home fits into one of  
these groups or if there is a local code or state law requiring a certain  
temperature water at the hot water tap, then you must take special  
precautions. In addition to using the lowest possible temperature setting  
that satisfies your hot water needs, a means such as a mixing valve,  
shall be used at the hot water taps used by these people or at the  
water heater. Mixing valves are available from your local plumbing  
contractor. Follow manufacturer’s instructions for installation of the  
valves. Before changing the factory setting on the thermostat, read  
the “Temperature Regulation” section in this manual.  
1. Turn off the heater electrical supply. Do not attempt to adjust  
thermostat with power on.  
2. Remove the thermostat access panels and covers from the  
thermostats. Do not remove the plastic personnel protectors covering  
the thermostats.  
3. Using a flat tip screwdriver, rotate the adjustment knob to the desired  
temperature setting.  
4. Replace the covers and access panels and turn on heater electrical  
supply.  
THIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE  
THERMOSTAT TO CONTROL WATER TEMPERATURE. HOT  
WATER TEMPERATURES DESIRED FOR AUTOMATIC  
DISHWASHER AND LAUNDRY USE CAN CAUSE SCALDS  
RESULTING IN SERIOUS PERSONAL INJURYAND/OR DEATH.  
THETEMPERATUREATWHICHINJURYOCCURSVARIES WITHTHE  
PERSON’SAGEANDTHETIME OFTHE EXPOSURE. THE SLOWER  
RESPONSETIME OF CHILDREN,AGED OR DISABLED PERSONS  
INCREASES THE HAZARDS TO THEM. NEVER ALLOW SMALL  
CHILDRENTO USEAHOT WATER TAP, OR TO DRAW THEIR OWN  
BATH WATER. NEVER LEAVE A CHILD OR DISABLED PERSON  
UNATTENDED INABATHTUB OR SHOWER.  
Temperature  
Settings  
Time to Produce 2nd & 3rd  
Degree Burns on Adult Skin  
About 1/2 second  
160°F(71°C)  
150°F (66°C)  
140°F (60°C)  
130°F (54°C)  
120°F (49°C)  
80°F (27°C)  
About 1-1/2 seconds  
Less than 5 seconds  
About 30 seconds  
It is recommended that lower water temperatures be used to avoid the  
risk of scalding. It is further recommended, in all cases, that the water  
temperature thermostat (See Figure 3) be set for the lowest temperature  
which satisfies your hot water needs. This will also provide the most  
energy efficient operation of the water heater. Thermostat(s) are  
factory set at 120°F (49°C) unless specified differently by state  
requirements.  
More than 5 minutes  
- - - - - - - - - - - - - - - -  
FIGURE7.  
11  
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FOR YOUR INFORMATION  
THERMALEXPANSION  
c. A sulfate reducing bacteria which has accumulated within the water  
heater (this harmless bacteria is nontoxic to humans).  
d. An excess of active hydrogen in the tank. This is caused by the  
corrosion protective action of the anode.  
Smelly water may be eliminated or reduced in some water heater  
models by replacing the anode(s) with one of less active material, and  
then chlorinating the water heater tank and all hot water lines. Contact  
the local water heater supplier or service agency for further information  
concerning anAnode Replacement Kit and this chlorination treatment.  
If the smelly water persists after the anode replacement and chlorination  
treatment, we can only suggest that chlorination or aeration of the  
water supply be considered to eliminate the water problem.  
Water supply systems may, because of such events as high line  
pressure, frequent cut-offs, the effects of water hammer among  
others, have installed devices such as pressure reducing valves, check  
valves, back flow preventers, etc. to control these types of problems.  
When these devices are not equipped with an internal by-pass, and no  
other measures are taken, the devices cause the water system to be  
closed. As water is heated, it expands (thermal expansion) and closed  
systems do not allow for the expansion of heated water.  
Do not remove the anode leaving the tank unprotected. By  
doing so, all warranty on the water heater tank is voided.  
“AIR” IN HOT WATER FAUCETS  
The water within the water heater tank expands as it is heated and  
increases the pressure of the water system. If the relieving point of  
the water heater’s temperature-pressure relief valve is reached, the  
valve will relieve the excess pressure. The temperature-pressure  
relief valve is not intended for the constant relief of thermal  
expansion. This is an unacceptable condition and must be corrected.  
It is recommended that any devices installed which could create a  
closed system have a by-pass and/or the system have an expansion  
tank or device to relieve the pressure built by thermal expansion in the  
water system. Expansion tanks are available for ordering through a  
local plumbing contractor. Contact the local water heater supplier or  
service agency for assistance in controlling these situations.  
HYDROGEN GAS: Hydrogen gas can be produced in a hot water  
system that has not been used for a long period of time (generally two  
weeks or more). Hydrogen gas is extremely flammable and explosive.  
To prevent the possibility of injury under these conditions, we  
recommend the hot water faucet, located farthest away, be opened  
for several minutes before any electrical appliances which are  
connected to the hot water system are used (such as a dishwasher or  
washing machine). If hydrogen gas is present, there will probably be  
an unusual sound similar to air escaping through the pipe as the hot  
water faucet is opened. There must be no smoking or open flame near  
the faucet at the time it is open.  
STRANGESOUNDS  
Possible noises due to expansion and contraction of some metal parts  
during periods of heat-up and cool-down do not necessarily represent  
harmful or dangerous conditions.  
OPERATIONAL CONDITIONS  
SMELLYWATER  
In each water heater there is installed at least one anode rod (see  
parts sections) for corrosion protection of the tank. Certain water  
conditions will cause a reaction between this rod and the water. The  
most common complaint associated with the anode rod is one of a  
“rotten egg smell” in the hot water. This odor is derived from hydrogen  
sulfide gas dissolved in the water. The smell is the result of four  
factors which must all be present for the odor to develop:  
HIGHWATERTEMPERATURESHUTOFFSYSTEM  
A non-adjustable high temperature limit control operates before steam  
temperatures are reached. The high limit is in the same area as the  
upper thermostat and must be reset manually when it operates.  
BECAUSE THE HIGH LIMIT OPERATES ONLY WHEN  
ABNORMALLYHIGH WATER TEMPERATURESARE PRESENT, IT  
ISIMPORTANTTHATAQUALIFIEDSERVICEAGENTBECONTACTED  
TODETERMINETHEREASONFOROPERATIONBEFORERESETTING.  
a. A concentration of sulfate in the supply water.  
b. Little or no dissolved oxygen in the water.  
PERIODIC MAINTENANCE  
The anode rod is used to protect the tank from corrosion. Most hot  
water tanks are equipped with an anode rod. The submerged rod  
sacrifices itself to protect the tank. Instead of corroding the tank,  
water ions attack and eat away the anode rod. This does not affect  
the water’s taste or color. The rod must be maintained to keep the tank  
in operating condition.  
ANODE ROD INSPECTION  
Anode deterioration depends on water conductivity, not necessarily  
water condition. Acorroded or pitted anode rod indicates high water  
conductivity and should be checked and/or replaced more often then  
an anode rod that appears to be intact. Replacement of a depleted  
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The water heater should be drained if being shut down during freezing  
temperatures. Also periodic draining and cleaning of sediment from the  
tank may be necessary.  
anode rod can extend the life of your water heater. Inspection should  
be conducted by a qualified technician, and at a minimum should be  
checked annually after the warranty period.  
1. Turn electrical supply “OFF”.  
TEMPERATURE-PRESSURE  
RELIEF VALVE OPERATION  
2. CLOSE the cold water inlet valve to the water heater.  
3. OPEN a nearby hot water faucet and leave open to allow for  
draining.  
4. Connect a hose to the drain valve and terminate to an adequate  
drain.  
5. OPEN the water heater drain valve to allow for tank draining.  
NOTE: If the water heater is going to be shut down and  
drained for an extended period, the drain valve should be  
left open with hose connected allowing water to terminate  
to an adequate drain.  
6. Close the drain valve.  
The temperature-pressure relief valve must be manually operated at  
least once a year.  
7. Follow the instructions in the “Filling the Water Heater” section.  
When checking the temperature-pressure relief valve operation, make  
sure that (1) no one is in front of or around the outlet of the temperature-  
pressure relief valve discharge line, and (2) that the water discharge  
will not cause any property damage, as the water may be extremely  
hot, see Figure 8.  
DRAIN VALVE WASHER REPLACEMENT  
(See Figure 9)  
1. Follow “Draining” instructions.  
2. Turning counter clockwise (  
screw handle.  
), remove the hex cap below the  
3. Remove the washer and put the new one in place.  
4. Screw the handle and cap assembly back into the drain valve and  
retighten using a wrench. DO NOT OVER TIGHTEN.  
5. Follow instructions in the “Filling The Water Heater” section.  
6. Check for leaks.  
FIGURE8.  
If after manually operating the valve, it fails to completely reset and  
continues to release water, immediately close the cold water inlet to  
the water heater, follow the draining instructions, and replace the  
temperature-pressure relief valve with a new one.  
If the temperature-pressure relief valve on the appliance weeps or  
discharges periodically, this may be due to thermal expansion. You  
may have a check valve installed in the water line or a water meter  
with a check valve. Consult your local water supplier or service  
agency for further information. Do not plug the temperature-pressure  
relief valve.  
DRAINING  
FIGURE 9.  
SERVICE  
If a condition persists or you are uncertain about the operation of the  
water heater contact a service agency.  
Use this guide to check a “Leaking” water heater. Many suspected  
“Leakers” are not leaking tanks. Often the source of the water can be  
found and corrected.  
If you are not thoroughly familiar with your water heater and safety  
practices, contact a qualified installer to check the water heater.  
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LEAKAGE CHECKPOINTS  
Read this manual first. Then before checking the water heater make  
sure the electrical power supply has been turned “OFF” before checking  
the tank for leakage.  
B
*A. Condensation and dripping may be seen on pipes if the water  
temperature is low in humid weather or pipe connections may be  
leaking.  
A
A
*B. The anode rod fitting may be leaking.  
C. Small amounts of water from temperature-pressure relief valve  
may be due to thermal expansion or high water pressure in your  
area. If the valve is not piped to an open drain the released water  
could be mistaken for a leaking heater.  
D
C
*D. The temperature-pressure relief valve may be leaking at the tank  
fitting.  
E. Water on the side of the tank may be condensation due to the  
panel or insulation not being in place.  
E
F. Water from a drain valve may be due to the valve being slightly  
opened.  
*G. The drain valve may be leaking at the tank fitting.  
E
*H. Water in the water heater bottom or on the floor 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.  
Leakage from other appliances, water lines, or ground seepage  
should also be checked.  
G
*
To check where threaded portion enters tank, insert cotton swab  
between jacket opening and fitting. If cotton is wet, follow  
“Draining” instructions in the “Periodic Maintenance” section and  
then remove fitting. Put pipe dope or teflon tape on the threads  
and replace. Then follow “Filling the Water Heater” instructions in  
the “Installing the New Water Heater” section.  
H
F
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REPAIR PARTS LIST  
Key No. Part Description  
11  
1
2
Upper Heating Element (If Dual Element Unit)  
8
Lower Heating Element  
Element Gasket  
3
4
Lower Thermostat (If Dual Element Unit)  
Upper Thermostat w/ECO (If Dual Element Unit)  
Lower Thermostat w/ECO (If Single Element Unit)  
Outer Door(s)  
12  
14  
5
14  
6
7
8
Inlet Tube  
9
Drain Valve  
10  
11  
12  
13  
14  
15  
16  
17  
*
Drain Valve Washer  
Anode Rod  
Anode Outlet/Heat Trap (If Applicable)  
Temperature-Pressure Relief Valve  
External Heat Trap Nipples (If Applicable)  
Pipe Insulation (If Applicable)  
T&P Insulation (If Applicable)  
Drain Pan w/Side Drain  
16  
7
5
1
3
Instruction Manual  
*Not Illustrated  
6
4
2
3
Now that you have purchased this water heater, should a need  
ever exist for repair parts or service, simply contact the company  
it was purchased from or the manufacturer listed on the rating  
plate on the water heater.  
15  
9
10  
Be sure to provide all pertinent facts when you call or visit.  
Selling prices will be furnished on request or parts will be  
shipped at prevailing prices and you will be billed accordingly.  
The model number of your Water Heater will be found on the  
rating place located above or adjacent to outer door.  
17  
DRAIN PAN  
WHEN ORDERING REPAIR PARTS, ALWAYS GIVE THE  
FOLLOWING INFORMATION:  
MODEL NUMBER  
SERIAL NUMBER  
PART DESCRIPTION  
THIS ISA REPAIR PARTS LIST, NOTAPACKING LIST.  
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TROUBLESHOOTING GUIDELINES  
These guidelines should be utilized by a qualified service agent.  
Problem  
Cause  
Solution  
Tighten threaded connections.  
Improperly sealed, hot or cold supply connection,  
relief valve or drain valve.  
WATER LEAKS  
(See Leakage Checkpoints on 14)  
Inspect other appliances near water heater.  
Leakage from other appliances or water lines.  
Thermal expansion in closed water system.  
Improperly seated valve.  
Install thermal expansion tank  
(DO NOT plug T&P valve).  
LEAKING TEMPERATURE  
AND PRESSURE  
RELIEF VALVE  
Check relief valve for proper operation  
(DO NOT plug T&P valve).  
Drain and flush heater thoroughly, then refill.  
Chlorinate water supply.  
High sulfate or mineral content in water supply.  
Bacteria in water supply.  
HOT WATER ODORS  
(CAUTION: UNAUTHORIZED REMOVAL OF THE  
ANODE(S) WILL VOID THE WARRANTY FOR  
FURTHER INFORMATION, CONTACT YOUR  
DEALER)  
Turn disconnect switch on or contact  
electrician.  
Power supply to heater is not on.  
NOT ENOUGH  
OR  
NO HOT WATER  
Refer to temperature regulation.  
Reduce hot water use.  
Thermostat set too low.  
Heater undersized.  
Allow more time for heat to reheat.  
Have plumber check and repair leaks.  
Incoming water is usually cold (Winter).  
Leaking hot water from pipes or fixtures.  
High temperature limit switch activated.  
Contact dealer to determine cause. See  
temperature regulation.  
Thermostat set too high.  
Refer to temperature regulation.  
HOT WATER TOO HOT  
High temperature limit switch activated.  
Contact dealer to determine cause. See  
temperature regulation.  
Scale accumulation on elements.  
Sediment build-up on tank bottom.  
Contact dealer to clean or replace elements.  
Drain and flush heater thoroughly, then refill.  
WATER HEATER SOUNDS  
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RESIDENTIAL ELECTRIC WARRANTY  
THIS WARRANTY IS APPLICABLE TO THE ORIGINAL  
This warranty shall apply only when the heater is:  
OWNER ONLY. In accordance with the warranty terms  
and conditions specified below.  
owned by the original purchaser;  
installed for indoor operation only;  
used at temperatures not exceeding the maximum  
calibrated setting of its thermostat;  
used at water pressure not exceeding the working  
pressure shown on the heater;  
filled with potable water, free to circulate at all times  
and with the tank free of damaging water sediment  
or scale deposits;  
used in a non-corrosive and non-contaminated  
atmosphere;  
used with factory approved anode(s) installed;  
in its original installation location;  
in the United States, its territories or possessions,  
and Canada;  
sized in accordance with proper sizing techniques  
for residential water heaters;  
bearing a rating plate which has not been altered,  
defaced or removed except as required by the  
warrantor;  
used in an open system or in a closed system with  
a properly sized and installed thermal expansion tank;  
connected to the proper voltage or:  
A. O. Smith Water Heaters (the warrantor) will furnish the  
ORIGINAL OWNER, 1) a replacement A. O. Smith water  
heater of equivalent size and current model if the glasslined  
tank in this water heater leaks and, 2) a replacement part  
for any component part which fails.  
THE A. O. SMITH WATER HEATERS REPLACEMENT  
MODEL OR PART WILL BE WARRANTED FOR ONLY THE  
UNEXPIRED PORTION OF THE ORIGINAL WARRANTY.  
The warranty period will be determined by the original date  
of purchase of the water heater, or in the absence of a Bill  
of Sale verifying said date, from the date of manufacture  
indicated on rating plate affixed to this water heater. This  
warranty is not transferrable and applies to models listed  
below:  
Series  
Tank  
Parts  
Conservationist®  
10-year  
10-year  
PXHT, PXHS  
ProMax® 10-Year Models 10-year  
6-year  
PCRT, PCRS, PCT, PCS, PCL, PCJ, PLJC, PLSC  
ProMax® 6-Year Models 6-year  
ECRT, ECRS, ECT, ECS, ECL,  
ECJ, ELJC, ESTT, ELSC  
6-year  
operated at the factory rated input;  
installed with no attempted, nor actual modification  
or alteration of the water heater’s design in any way,  
including but not limited to, the attachment of non-  
company approved appliances or equipment.  
When the water heater has been used for other than single  
family residential application;  
Any accident to the water heater or any part thereof  
(including freezing, fire, floods, or lightning), any misuse,  
abuse or alteration of it, any operation of it in a modified  
form, any operation of the water heater on desalinated  
(deionized) water, or any damage caused by attempts  
to repair tank leaks or parts, will void this warranty. This  
warranty does not cover water heaters replaced for  
cosmetic reasons or for reasons of noise, taste, odor,  
discolored and/or rusty water. This warranty does not  
apply to water heaters used to heat pools, whirlpools or  
hot tubs or used for space heating where its sizing does  
not conform with specifications of the heating component  
manufacturer.  
1. The tank warranty shall be reduced to 1 year for 6 year  
models and to 3 years for 10 year models.  
2. The parts warranty shall be reduced to 1 year for all  
models.  
CONDITIONS AND EXCEPTIONS  
This warranty shall apply only when the water heater is  
installed and operated in accordance with 1) all local fire  
codes and plumbing codes, ordinances and regulations, 2)  
the printed instructions provided with it, 3) good industry  
practices, and 4) proper safety practices such as but not  
limited to a properly sized drain pan if installed in an area  
where leakage from the tank or its connections would result  
in damage to the area adjacent to the heater. In addition, a  
new temperature and pressure relief valve, certified by the  
Canadian GasAssociation must have been properly installed  
and piped to the nearest drain.  
This warranty gives you specific legal rights, and you  
may have other rights which vary under the laws of each  
state. If any provision of this warranty is prohibited or  
invalid under applicable state law, that provision shall be  
ineffective to the extent of the prohibition or invalidity  
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Dealer replacements are made subject to in-warranty  
validation by warrantor.  
without invalidating the remainder of the affected provision  
or the other provisions of this warranty.  
PROOF OF PURCHASEAND PROOF OF INSTALLATION  
DATE ARE REQUIRED TO SUPPORT WARRANTY  
CLAIM FROM ORIGINAL OWNER. THIS FORM DOES  
NOT CONSTITUTE PROOF OF PURCHASE OR PROOF  
OF INSTALLATION.  
SERVICE AND LABOR RESPONSIBILITY  
UNDER THIS LIMITED WARRANTY, THE WARRANTOR  
WILL PROVIDE ONLY A REPLACEMENT WATER  
HEATER OR PART THEREOF. THE OWNER IS  
RESPONSIBLE FOR ALL OTHER COSTS. Such costs  
may include but are not limited to:  
DISCLAIMERS  
NO EXPRESSED WARRANTY HAS BEEN OR WILL BE  
MADE IN BEHALF OF THE WARRANTOR WITH  
RESPECTTO THE MERCHANTABILITY OF THE HEATER  
OR THE INSTALLATION, OPERATION, REPAIR OR  
REPLACEMENT OF THE HEATER OR PARTS. THE  
WARRANTOR SHALL NOT BE RESPONSIBLE FOR  
WATER DAMAGE, LOSS OF USE OF THE UNIT,  
INCONVENIENCE, LOSS OR DAMAGE TO PERSONAL  
PROPERTY, OR OTHER CONSEQUENTIAL DAMAGE.  
THE WARRANTOR SHALL NOT BE LIABLE BY VIRTUE  
OF THIS WARRANTY OR OTHERWISE FOR DAMAGE  
TO ANY PERSONS OR PROPERTY, WHETHER DIRECT  
OR INDIRECT, AND WHETHER ARISING IN CONTRACT  
OR IN TORT.  
a. Labor charges for service, removal, or reinstallation  
of the water heater or part thereof.  
b. Shipping and delivery charges for forwarding the new  
water heater or replacement part from the nearest  
distributor and returning the claimed defective heater  
or part to such distributor.  
c. All cost necessary or incidental for handling and  
administrative charges, and for any materials and/or  
permits required for installation of the replacement  
heater or part.  
LIMITATION ON IMPLIED WARRANTIES  
Should governmental regulations or industry standards  
prohibit the Manufacturer from furnishing a comparable  
model replacement under this warranty, the Owner will be  
furnished with the closest comparable water heater meeting  
the then current governmental regulations and industry  
standards. A supplementary fee may be assessed to cover  
the additional cost associated with the changes made to  
meet applicable regulations and standards.  
Implied warranties, including any warranty of merchan-  
tability imposed on the sale of this heater under state  
law are limited to one year duration for the heater or  
any of its parts. Some states do not allow limitations  
on how long an implied warranty lasts, so the above  
limitations may not apply to you.  
CLAIM PROCEDURE  
Any claim under this warranty should be initiated with  
the dealer who sold the heater, or with any other dealer  
handling the warrantor’s products. If this is not practical,  
the owner should contact: A.O. Smith Corporation,  
5621 W. 115th Street, Alsip, Illinois 60803. Phone:  
IMPORTANT INFORMATION  
Model Number _______________________________  
Serial Number _______________________________  
INSTALLATION INFORMATION  
For Canadian customers contact: A.O. Smith  
Enterprises LTD., P.O. Box 310, 768 Erie Street,  
Stratford, Ontario N5A6T3 or phone: 1.800.265.8520  
Date Installed _______________________________  
Company’s Name ____________________________  
Street or P.O. Box ____________________________  
City, State, and Zip Code ______________________  
Phone Number ______________________________  
Plumber’s Name _____________________________  
Replacement Parts may be ordered through authorized  
servicers or distributors. Refer to your local Yellow  
Pages for where to call or contactA.O. Smith Corporation,  
5621 W. 115th Street, Alsip, Illinois 60803.  
Phone: 1.800.433.2545 or visit our website at:  
The warrantor will only honor replacement with identical  
or similar water heater or parts thereof which are  
manufactured or distributed by the warrantor.  
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NOTES:  
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