AO Smith Fan 160M User Guide

MODELS HW-120M, 160M, 200M, 225M  
COMMERCIAL GAS COPPER HEAT EXCHANGER WATER HEATER  
BURKAY UP-FLOW MODELS  
Including Models with Intermittent Pilot Ignition (I.I.D.)  
Installation Operation Maintenance Limited Warranty  
WARNING: If the information in these  
instructions are not followed exactly, a fire  
or explosion may result causing property  
damage, personal injury or death.  
—Do not store or use gasoline or other  
flammable vapors and liquids in the  
vicinity of this or any other appliance.  
—WHAT TO DO IF YOU SMELL GAS  
CAUTION  
Do not try to light any appliance.  
Do not touch any electrical switch;  
TEXT PRINTED OR OUTLINED IN RED CONTAINS  
INFORMATION RELATIVE TO YOUR SAFETY. PLEASE READ  
THOROUGHLY BEFORE USING APPLIANCE.  
do not use any phone in your  
building.  
Immediately call your gas supplier  
from a neighbor’s phone. Follow  
the gas supplier’s instructions.  
If you cannot reach your gas  
supplier, call the fire department.  
A DIVISION OF A.O. SMITH CORPORATION  
McBEE, SOUTH CAROLINA, USA  
RENTON, WA, USA  
STRATFORD, ONTARIO, CANADA  
— Installation and service must be  
performed by a qualified installer,  
service agency or the gas supplier.  
VELDHOVEN, THE NETHERLANDS  
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER  
AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE  
PART NO. 212626-000  
PRINTED IN U.S.A. 0905  
SUPERSEDES PART NO. 192011-000 REV.4  
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ROUGH-IN-DIMENSIONS  
TABLE 1 - ROUGH-IN DIMENSIONS  
Models  
Dimensions Inches  
HW-120M  
HW-160M  
Inches  
HW-200M  
Inches  
53 1/4  
33 1/8  
27 1/8  
20 3/4  
5 1/2  
10  
11 13/16  
7
HW-200M  
Inches  
mm  
1254  
772  
600  
527  
140  
254  
300  
152  
678  
527  
mm  
1273  
772  
600  
527  
140  
254  
300  
178  
678  
527  
mm  
1353  
841  
689  
527  
140  
254  
300  
178  
678  
527  
mm  
1524  
841  
689  
527  
140  
254  
300  
178  
678  
527  
A
B
C
D
E
F
G
H
49 3/8  
30 3/8  
23 5/8  
20 3/4  
5 1/2  
10  
11 13/16  
6
50 1/8  
30 3/8  
23 5/8  
20 3/4  
5 1/2  
10  
11 13/16  
7
60  
33 1/8  
27 1/8  
20 3/4  
5 1/2  
10  
11 13/16  
7
J
K
26 11/16  
20 3/4  
26 11/16  
20 3/4  
26 11/16  
20 3/4  
26 11/16  
20 3/4  
L
M
1 1/4 NPT  
1 NPT  
1 1/4 NPT  
1 NPT  
1 1/4 NPT  
1 NPT  
1 1/4 NPT  
1 NPT  
N
1/2 NPT  
1/2 NPT  
1/2 NPT  
1/2 NPT  
W
1 3/4  
44  
1 3/4  
44  
1 3/4  
44  
1 3/4  
44  
Approx.  
Shipping  
Weight  
120 lbs.  
54 Kg. 155 lbs. 70 Kg. 165 Lbs. 75 Kg.  
175 lbs.  
79 Kg.  
HEATER PERFORMANCE DATA  
NOTE: To compensate for the effects of high altitude areas above 2000 feet, input rating, and therefore recovery ratings, should be  
reduced approximately 4% for each 1000 feet above sea level.  
TABLE 2 - RECOVERY CAPACITIES  
U.S. Gallons/Hrs. and Litres/Hr. at TEMPERATURE RISE INDICATED  
Input  
Btuh  
F°  
20F° 30F° 36F° 40F°  
50F° 54F° 60F° 70F° 72F° 80F° 90F° 100F° 108F° 110F° 120F° 126F° 130F° 140F°  
Model  
KW C° 11.1C° 16.6C° 20C° 22.2C° 27.7C° 30C° 33.3C° 38.8C° 40C° 44.4° 50C° 55.5C° 60C° 61.1C° 66.6C° 70C° 72.2C° 77.7C°  
120,000  
160,000  
199,000  
225,000  
GPH 605  
35 LPH 2290 1527 1272 1145  
GPH 777 518 432 388  
47 LPH 2941 1961 1634 1471  
GPH 987 658 548 494  
58 LPH 3737 2491 2076 1869  
GPH 1096 731 609 548  
66 LPH 4149 2766 2305 2074  
403  
336  
303  
242  
916  
311  
224  
848  
288  
202  
763  
259  
980  
329  
173  
654  
222  
840  
282  
168  
636  
216  
817  
274  
151  
573  
194  
735  
247  
934  
274  
134  
509  
173  
654  
219  
830  
244  
121  
458  
155  
588  
197  
747  
219  
830  
112  
242  
144  
545  
183  
692  
203  
768  
110  
416  
141  
535  
179  
679  
199  
754  
101  
382  
129  
490  
165  
623  
183  
691  
96  
93  
86  
HW-120M  
364  
123  
467  
157  
593  
174  
659  
352  
120  
452  
152  
575  
169  
638  
327  
111  
420  
141  
534  
157  
593  
HW-160M  
1176 1089  
395 366  
HW-200M  
1495 1384 1246 1068 1038  
438 406 365 313 304  
HW-2250M  
1659 1537 1383 1185 1152 1037 922  
Recovery rating of models shown in chart above are obtained by actual efficiency test data by recognized Certification Agency.  
NOTE: Recovery rate shown on each models rating plate is based on the requirements of ANSI Standard Z21.10.3, which stipulates  
the data to be based on energy efficiency of 75%.  
TABLE 3 - CAPACITY AND GAS AND ELECTRIC CHARACTERISTICS  
Manifold Pressure  
Maximum Supply Pressure Electrical Characteristics  
Model  
Type of Gas  
Inches W.C.  
kPa  
0.87  
2.49  
Inches W.C.  
10.5  
kPa  
2.61  
3.23  
Volts/Hz  
120/60  
120/60  
Amperes  
HW-120M thru 225M  
HW-120M thru 200M  
NATURAL  
PROPANE  
3.5  
10  
<5  
<5  
13.0  
Minimum Supply Pressure, Natural Gas: 4.5 inches W.C. (1.12 kPa)  
Minimum Supply Pressure, Propane Gas: 11.0 inches W.C. (1.74 kPa)  
Minimum Pressure must be maintained under both load and no load (static and dynamic) conditions.  
2
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FOREWORD  
The factory warranty will be void if the unit(s) have been improperly  
installed or operated.  
This design complies with the latest edition of the ANSI Standard  
Z21.10.3 for gas water heaters Vol. III Storage Water Heaters  
with input ratings above 75,000 BTU per hour Circulating and  
Instantaneous.  
In addition to these instructions, the boiler(s) shall be installed in  
accordance with those installation regulations in force in the local  
area where the installation is to be made. These shall be carefully  
followed in all cases. Authorities having jurisdiction should be  
consulted before installations are made.  
Detailed installation diagrams are in this manual. These diagrams  
will serve to provide the installer with a reference for the materials  
and method of piping suggested. IT IS ESSENTIAL THAT ALL  
WATER AND GAS PIPING AND THE ELECTRICAL WIRING BE  
INSTALLEDAND CONNECTEDAS SHOWN IN THE DIAGRAMS.  
In absence of local codes, the installation must comply with the  
latest editions.  
You should thoroughly read and understand this manual before  
installation and operation of this unit.  
In the United States:  
The National Fuel Gas Code, ANSI Z223.1 and the National  
Electric Code, NFPA 70.  
CHECK THE DIAGRAMS THOROUGHLY BEFORE STARTING  
INSTALLATION TO AVOID POSSIBLE ERRORS AND TO  
MINIMIZE TIME AND MATERIALS COST.  
In Canada:  
Particular attention should be given to the installation of  
thermometers at the locations indicated in the diagrams as these  
are necessary for checking the operation of the heater.  
The Installation Code CAN/CGA B149.1 and .2 (latest edition)  
and the Canadian Electric Code, CSA C22.1.  
These are available from the Canadian Standards Association,  
8501 East Pleasant Valley Road, Cleveland, OH 44131, USA, or,  
Canadian Gas Association Laboratories, 55 Scarsdale Road, Don  
Mills, Ontario M3B 2R3, Canada.  
MAKE SURE THE GAS ON WHICH THE HEATER WILL  
OPERATE IS THE SAMEAS THAT SPECIFIED ON THE HEATER  
MODEL AND RATING PLATE.  
TABLE OF CONTENTS  
PAGE  
PAGE  
ROUGH-IN DIMENSIONS ..................................................................  
FOREWORD .......................................................................................  
GENERAL SAFETY INFORMATION ..................................................  
2
3
3
PIPING DIAGRAMS ............................................................................ 11-13  
Gas Connections ........................................................................... 14-15  
Electrical Information ..................................................................... 15-16  
Precautions .................................................................................... 3-4  
OPERATION ........................................................................................  
Important .......................................................................................  
General ...........................................................................................  
Filling ..............................................................................................  
Purging Of Gas Line ......................................................................  
Operating Instructions For I.I.D Models. .......................................  
Checking And Adjusting The Input .................................................  
SERVICE INFORMATION ..................................................................  
Pilot And Main Burner Maintenance ...............................................  
17  
17  
17  
17  
17  
18  
19  
20  
20  
Grounding Instructions ...................................................................  
Chemical Vapor Corrosion .............................................................  
Liquid Petroleum Models ................................................................  
High Altitude Installations ...............................................................  
FEATURES .........................................................................................  
Automatic Gas Shutoff Control .......................................................  
Protector Switch (Coil High Limit) ...................................................  
Thermal Balancer ...........................................................................  
4
4
4
4
5
5
5
5
Intermittent Ignition Control Module ................................................ 5-6  
I.I.D. Pilot Burner ........................................................................... 20-21  
Circulating Pump ............................................................................  
Tank Temperature Control (Not Supplied) ......................................  
Safety Flow Switch (Not Supplied) ................................................. 6-7  
6
6
Protector Switch (Coil High Limit-All Heaters) ...............................  
Tank Temperature Control ..............................................................  
Automatic Gas Shutoff Control .....................................................  
Thermal Balancer ...........................................................................  
21  
21  
21  
21  
Drain Valve (Not Supplied) .............................................................  
Thermometers (Not Supplied) ........................................................  
INSTALLATION INSTRUCTIONS .......................................................  
Important ........................................................................................  
Required Ability ..............................................................................  
Location .........................................................................................  
Installation Clearances ...................................................................  
Levelling .........................................................................................  
7
7
8
8
8
8
8
8
Inspecting The Heat Exchanger And Venting System .................. 21-22  
Gas Pressure Regulator ................................................................  
Relief Valve ...................................................................................  
Circulating Pump ............................................................................  
Electrical Service ...........................................................................  
Replacement Parts ........................................................................  
PREVENTIVE MAINTENANCE ...........................................................  
Recommended Procedure For Periodic Removal Of Lime  
22  
22  
22  
22  
22  
22  
Air Requirements ........................................................................... 8-9  
Venting ...........................................................................................  
Relief Valve .................................................................................... 9-10  
Hard Water .....................................................................................  
Closed Water System ....................................................................  
Water Line Connections ................................................................  
Water (Potable) Heating ................................................................  
9
Deposits From Coil Type Commercial Water Heaters ................. 22-23  
Deliming Solvents ..........................................................................  
Removing Light Deposits ..............................................................  
23  
23  
10  
10  
10  
10  
Heavy Lime Deposits ................................................................... 23-24  
CHECKOUT ........................................................................................ 24-27  
LIMITED WARRANTY ........................................................................  
28  
GENERAL SAFETY INFORMATION  
3. IF DAMAGED.  
PRECAUTIONS  
4. FIRING WITHOUT WATER.  
5. SOOTING.  
If the unit is exposed to the following, do not operate heater until  
all corrective steps have been made by a qualified serviceman:  
KEEP THE HEATER AREA CLEAR AND FREE FROM  
COMBUSTIBLE MATERIALS, GASOLINE AND OTHER  
FLAMMABLE VAPORSAND LIQUIDS. AREAAROUND HEATER  
MUST NOT CONTAIN OBSTRUCTING MATERIAL TO THE  
FLOW OF COMBUSTION AND VENTILATING AIR.  
1. FLOODING TO LEVEL OF BURNER OR CONTROLS OR  
HIGHER.  
2. EXPOSURE TO FIRE.  
3
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SHOULD OVERHEATING OCCUR OR THE GAS SUPPLY FAIL  
TO SHUT OFF, TURN OFF THE MANUAL GAS CONTROL  
VALVE TO THE APPLIANCE.  
HIGH ALTITUDE INSTALLATIONS  
WARNING  
INSTALLATIONSABOVE 2000 FEETREQUIRE REPLACEMENT  
OF THE BURNER ORIFICE IN ACCORDANCE WITH SECTION  
8.1.2 OFTHE NATIONALFUEL GAS CODE (ANSI Z223.1). FOR  
CANADIAN INSTALLATIONS CONSULT CANADIAN  
INSTALLATION CODES AND CAN/CGA B149. FAILURE TO  
REPLACE THE ORIFICES WILL RESULT IN IMPROPER AND  
INEFFICIENT OPERATION OF THE APPLIANCE RESULTING  
IN THE PRODUCTION OF INCREASED LEVELS OF CARBON  
MONOXIDE GAS IN EXCESS OF SAFE LIMITS WHICH COULD  
RESULT IN SERIOUS PERSONAL INJURY OR DEATH.  
Heater must be protected from freezing downdrafts during  
shutdown periods.  
GROUNDING INSTRUCTIONS  
This water heater must be grounded in accordance with the  
National Electric Code and/or local codes. These must be followed  
in all cases.  
This water heater must be connected to a grounded metal,  
permanent wiring system; or an equipment grounding conductor  
must be run with the circuit conductors and connected to the  
equipment grounding terminal or lead on the water heater.  
You should contact your gas supplier for any specific changes  
which may be required in your area.  
As elevation above sea level is increased, there is less oxygen  
per cubic foot of gas. Therefore, the heater input rate should be  
reduced at high altitudes for satisfactory operation with the reduced  
oxygen supply. Failure to make this reduction could result in an  
overfiring of the heater, causing sooting, poor combustion and/or  
unsatisfactory heater performance.  
CHEMICAL VAPOR CORROSION  
WARNING  
CORROSION OF THE FLUEWAYS AND VENT SYSTEM MAY  
OCCUR IF AIR FOR COMBUSTION CONTAINS CERTAIN  
CHEMICAL VAPORS. SUCH CORROSION MAY RESULT IN  
FAILURE AND RISK OF ASPHYXIATION.  
U.S. REQUIREMENTS  
Ratings specified by manufacturers for most appliances apply for  
elevations up to 2000 feet (610m). For elevations above 2000  
feet (610m), ratings must be reduced at the rate of 4% for each  
1000 feet (305m) above sea level. For example, if a heater is  
rated at 120,000 Btuh (35 Kwh) at sea level, to rate the heater at  
4000 feet (1219m), you subtract 4 (once for each thousand feet)  
x .04 (4% input reduction) x 120,000 (original rating) from the  
original rating. Therefore, to calculate the input rating at 4,000  
feet (121.9m): 4 x .04 x 120,000=19,200 Btuh (5.6 Kwh), 120,000  
(35 Kwh) - 19,200 (5.6Kwh)=100,000 Btuh (29.4 Kwh). At 6000  
feet (1829m) the correct input rating should be 91,200 Btuh (26.7  
Kwh).  
Spray can propellants, cleaning solvents, refrigerator and air  
conditioning refrigerants, swimming pool chemicals, calcium and  
sodium chloride (water softener salt), waxes, and process  
chemicals are typical compounds which are potentially corrosive.  
Do not store products of this sort near the heater. Also, air which  
is brought in contact with the heater should not contain any of  
these chemicals. If necessary, uncontaminated air should be  
obtained from remote or outside sources. The limited warranty is  
voided when failure of water heater is due to a corrosive  
atmosphere. (Refer to the limited warranty for complete terms  
and conditions.)  
CANADIAN REQUIREMENTS  
LIQUID PETROLEUM MODELS  
Appliances with inputs up to and including 400,000 BTU (117.2  
Kw) must be factory equipped with orifices for operation at specific  
elevations. Standard (sea level) orifices permit operation up to  
2000’ (610m) elevation. For operation between 2000’ (610m)  
and 4500’ (1370m) specify “HIGHALTITUDE OPERATION” when  
ordering the heater(s). For operation above 4500’ (2370m) consult  
factory before ordering.  
Water heaters for propane or liquefied petroleum gas (LPG) are  
different from natural gas models. A natural gas heater will not  
function safely on LP gas and no attempt should be made to  
convert a heater from natural to LP gas.  
LP gas must be used with great caution. It is highly explosive  
and heavier than air. It collects first in low areas making odor  
difficult to detect at nose level. If LP gas is present or even  
suspected, do not attempt to find the cause yourself. Go to a  
neighbor’s house, leaving your doors open to ventilate the house,  
then call your gas supplier or service agent. Keep area clear  
until a service call has been made.  
Field conversion for operation at altitudes other than that  
specified on the heater rating plate is not permitted.  
The input reduction is primarily achieved by reducing the size of  
the main burner orifice. To do this, the main burner orifices require  
replacement with orifices sized for the particular installation  
elevation. Correct orifice sizing and parts may be obtained from  
A.O. Smith Water Products Company. When ordering, be sure  
to state the model number and the altitude of the location where  
the water heater is being installed.  
At times you may not be able to smell an LP gas leak. One cause  
is odor fade, which is a loss of the chemical odorant that gives LP  
gas its distinctive smell. Another cause can be your physical  
condition, such as having a cold or diminishing sense of smell  
with age. For these reasons, the use of a propane gas detector  
is recommended.  
Upon completion of derating of the heater, adjustment to the gas  
pressure regulator may be required. See CHECKING THE INPUT  
section in this manual for inlet and manifold pressure  
requirements.  
IF YOU EXPERIENCE AN OUT-OF-GAS SITUATION, DO NOT  
TRY TO RELIGHT APPLIANCES YOURSELF. Only trained LP  
professionals should conduct the required safety checks in  
accordance with industry standards.  
Also due to the input rating reduction required at high altitudes,  
the output rating of the appliance is reduced and should be  
compensated for in the sizing of the equipment for the application.  
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FEATURES  
TABLE 4.  
Control Device  
Factory Setting  
Field Adjustment  
1950F (90.5°C) cut out temp.  
Fixed 1900F (87.7°C) cut in temp.  
2500F (121°C) cut out temp.  
Fixed 2000F (93.3°C) cut in temp.  
Field Supplied and Installed  
Heater Automatic Gas Shutoff Control  
Non-adjustable  
Heater Protector Switch  
Tank Temperature Control  
Safety Flow Switch  
Non-adjustable  
Adjust to Requirements  
Field Adjustable  
See Table 1  
AUTOMATIC GAS SHUTOFF CONTROL  
The automatic gas shutoff control, fig. 1, is an automatic safety  
device which activates at a water temperature of approximately  
1950F (90.5°C). This limits the water outlet temperature to a  
maximum of 2000F (87.7°C).  
The device is wired in series with the gas valve. The control will  
automatically reset when the water temperature cools to  
approximately 190oF (87.7°C).  
Should the automatic gas shutoff control activate during a heating  
cycle, the heater’s gas valve will close; extinguishing the main  
burners. The pilot burner will also be extinguished. The circulating  
pump will continue operating as long as the storage tank  
thermostat continues to “call for heat”. When the water  
temperature in the heater drops to 1800F (82.2°C) or below the  
control module will begin an ignition cycle which will relight the  
pilot burner and main burners. Re-ignition of the main burners  
will occur if the storage tank thermostat continues to call for heat.  
Otherwise, the normal operating cycle will resume on the  
thermostat’s next call for heat.  
FIGURE 2  
DO NOT RESET THIS SWITCH WITHOUT PERFORMING THE  
SYSTEM CHECKS OUTLINED UNDER PROTECTOR SWITCH  
IN THE SERVICE INFORMATION SECTION. ALSO, SEE CHART  
ONE UNDER THE CHECKOUT SECTION. IF NECESSARY,  
CALL A QUALIFIED SERVICEMAN. Once the cause of the  
protector switch activation has been determined and corrected, it  
will be necessary to restart the heater following the LIGHTING  
AND OPERATING instructions.  
THERMAL BALANCER  
The thermal balancer (standard on Models HW-200M and  
HW-225M, optional on Models HW-120M and HW-160M) is a  
snap-acting single-pole thermal relay used only on Cer-Temp 80  
Recovery systems. It gives immediate pump start but delay of  
pump shutoff for approximately 2 minutes. Residual heat in the  
heat exchanger is then recovered after shutdown. This improves  
efficiency and balances heater temperature with tank temperature  
at shutdown.  
AUTOMATIC GAS SHUTOFF CONTROL  
FIGURE 1  
INTERMITTENT IGNITION CONTROL MODULE  
The Honeywell S-8600 control module contain the electronic  
components of the system and also serve as a central wiring  
system for the controls mounted on the heater. The control module  
performs the following functions:  
PROTECTOR SWITCH (Coil High Limit)  
This heater is equipped with a manually reset protector switch,  
Figure 2, located under the small cover on the side of the jacket.  
This device provides positive shutdown of the heater in the event  
of heater or system malfunction. Should the surface temperature  
of the copper tubing heat exchanger reach 2500F (121.1°C), the  
protector switch will activate. The gas valve will close, and the  
pilot and main burners will be extinguished. To resume heater  
operation, the protector switch must be manually reset (remove  
the protector switch cover and push the reset button) after the  
coil surface temperature cools to less than 2000F(93.3°C).  
1. Checks for safe-start by sensing for a flame or false flame  
condition on start-up.  
2. Generates a potential of 15,000 volts for spark ignition of the  
pilot burner.  
3. Opens the pilot valve.  
5
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4. Discontinues ignition spark when the pilot flame is established. Follow the same oiling procedure if a replacement circulator is  
The S-8600 control used on propane gas models provides installed into the system.  
safety lockout if the pilot fails to ignite within the pilot flame  
establishing period. The S-8600 control used on natural gas  
models continues trial for ignition until pilot flame is established.  
TANK TEMPERATURE CONTROL  
(Not Supplied)  
5. After proof-of-pilot flame, opens the main valve.  
DANGER  
6. On a power loss, shuts the heater down. When power is  
USE ANTI-SCALD VALVE(S) in the hot water system to reduce  
the risks of scalds at points of use such as lavatories, sinks and  
restored it will begin a new ignition cycle.  
bathing facilities.  
7. On a loss of flame, shuts off main gas and starts trial for pilot  
ignition.  
The tank temperature control is located in the lower portion of the  
hot water storage tank, see PIPING DIAGRAMS. It is the primary  
operating control of the system and regulates the water  
temperature in the tank.  
The storage tank thermostat should have contact ratings that  
exceed the maximum electrical requirements of the system.  
Typically, the thermostat should have motor full load and locked  
rotor current ratings which exceed the total amount of current  
required to drive the pump(s) controlled by the thermostat.  
The thermostat should have a temperature range of 1000F  
(37.7°C) to 1800F (82.2°C) or more. The preferred initial setting  
for the storage tank thermostat is 1200F (48.8°C). However, for  
normal use, the thermostat should be adjusted to the lowest setting  
which produces an acceptable hot water supply temperature. This  
will always give the most energy efficient operation. Do not adjust  
the thermostat to achieve a storage temperature of 190oF (87.7°C)  
INTERMITTENT IGNITION CONTROL MODULE (I.I.D.)  
FIGURE 3  
or above. This action may cause the automatic gas shutoff control  
to activate shutting down the heater.  
Intermittent ignition device and circulator start and stop  
simultaneously as the tank thermostat contacts open and close.  
This basic action, water flowing whenever the burner operates,  
must not be altered.  
CIRCULATING PUMP  
Constant circulating pump operation of the heater voids the  
warranty. Constant water flow through the unit will “wash” away  
the copper’s natural protective coating. This is called velocity  
erosion. This erosion is not as great a problem when intermittent  
circulating operation is used per the recommended installation  
procedure. Constant circulation of water between the storage  
tank and the building is permissible as long as the water does not  
constantly flow through the heater.  
SAFETY FLOW SWITCH  
(Not Supplied)  
The safety flow switch is a safety device installed at the water  
outlet of the unit to prevent main burner operation in the event of  
inadequate water flow through the unit.  
Only all bronze circulators are used with commercial water heaters.  
An accessory package A.O.S. No. 211480 containing a safety  
flow switch is available for this application.  
Although circulators are oiled and operated by the manufacturer,  
THEY MUST BE OILED AGAIN BEFORE OPERATED. Oil the  
three oil cups (2 on the motor, 1 on the pump) as instructed by  
manufacturer. See fig. 4.  
This switch may be mounted in a horizontal pipe line or a vertical  
pipe line with upward water flow. Do not install the switch where  
the water flow is downward.  
Thereafter, lubricate the three oil cups at least once every 4  
months.  
For proper performance mount the switch in a section of pipe  
where there is a straight run of at least 5 pipe diameters on each  
side of the flow switch (i.e. do not locate adjacent to valves, elbows,  
orifices, etc.).  
The flow switch shall be mounted in a standard 1" x 1" x 1" tee for  
a 1" pipe application. For larger pipe sizes use a reducing tee in  
order to keep the switch as close to the pipe as possible. Install  
the flow switch in the branch (top) opening of the reducing tee  
and provide adequate paddle length in the flow stream. For  
example in a 2" pipe installation use a 2" x 2" x 1" reducing tee.  
For 1", 2" or 3" pipe use the paddle segments as supplied. For  
other pipe sizes (i.e. 1 1/4", 1 1/2", and 2 1/2") trim the paddle to  
the proper pipe size, see fig. 5. If a standard tee is used, install a  
face or hex bushing in the top opening. The paddle must be  
TYPICAL CIRCULATING PUMP  
FIGURE 4  
Use 2 or 3 teaspoonsful in bearing oil cups, and 10 or 12 drops in adjusted or trimmed to the size of the pipe in which it will be  
the motor oil cups. Use no. 20 non-detergent motor oil. installed.  
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CAUTION: The paddle must be trimmed at the dotted arc. It must not touch the pipe or any restrictions when installed.  
FIGURE 5  
The installer is cautioned to follow the manufacturer’s instructions  
CAUTION  
exactly when inserting this switch into a pipe tee. This is necessary  
Any part of the paddle must not touch the pipe or any restrictions  
in order to assure positive action of the switch with water flow.  
in the pipe. Screw the flow switch in position so the flat of the  
Once the minimum flow rate (Table 5) through the heater is  
paddle is at right angles to the flow. The arrow on the side case  
reached, the safety flow switch contacts close and consequently,  
must point in the direction of the flow.  
main burner operation is achieved.  
The safety flow switch may be field adjusted to obtain higher  
minimum flow rates than those shown in Table 5.  
DRAIN VALVE (Not Supplied)  
To adjust the flow rate setting:  
A drain valve must be obtained and installed on each heater and  
tank for draining purposes, see installation diagrams in this  
manual.  
1. Remove the flow switch cover.  
2. For higher flow rate—turn the range adjusting screw clockwise.  
3. For lower flow rate—turn the range adjusting screw  
counterclockwise.  
THERMOMETERS (Not Supplied)  
Thermometers should be obtained and field installed as shown  
in the installation diagrams.  
CAUTION  
The switch is factory set at approximately the minimum flow rate,  
see Table 5. It must not be set lower than the factory setting as  
this may result in the switch failing to return at a  
“no flow” condition.  
Thermometers are installed in the system as a means of detecting  
a possible liming condition in the heater. An increase of 50F over  
the normal temperature rise through the heater is an indication  
that lime is present. The term “temperature rise” designates the  
difference between the heater inlet and outlet water temperatures.  
4. Replace the flow switch cover.  
TABLE 5 - SAFETY FLOW SWITCH SETTINGS  
Minimum Flow Rate (GPM)  
An increase of 50F (3°C) above the recorded temperature rise  
may signify a liming condition in the coils or heat exchanger. Refer  
to PREVENTIVE MAINTENANCE section of this manual for  
deliming instructions.  
Contacts Close  
GPM LPM  
Contacts Close  
GPM  
0.3  
Pkg.  
No.  
Model  
HW-120M,160M  
HW-200M  
LPM  
1.1  
0.6  
4.2  
2.3  
211480  
211480  
15.9  
2.5  
9.5  
HW-225M  
5.8  
22.0  
3.7  
14.0  
211480  
Record temperature rise at initial start-up for future reference.  
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INSTALLATION INSTRUCTIONS  
For appliance installation in locations with elevations above 2,000  
feet (600M), refer to HIGH ALTITUDE INSTALLATIONS section  
of this manual for input reduction procedure.  
IMPORTANT  
Strict adherence to installation wiring diagrams shown in this  
manual is required to prevent constant pump operation when the  
system temperature control is satisfied, otherwise the warranty is  
void as stipulated under item 2a (6) of the LIMITED WARRANTY.  
INSTALLATION CLEARANCES  
These units are approved for installation in an alcove having  
minimum clearances from combustible construction of 44"  
(1,118mm) from top of the jacket, 6" (152.4mm) from sides, and  
6" (152.4mm) from rear and vent connections.  
REQUIRED ABILITY  
INSTALLATION OR SERVICE OF THIS WATER HEATER  
REQUIRES ABILITY EQUIVALENT TO THAT OF A LICENSED  
TRADESMAN IN THE FIELD INVOLVED. PLUMBING, AIR  
SUPPLY, VENTING, GAS SUPPLY AND ELECTRICAL WORK  
ARE REQUIRED.  
All models may be installed on combustible flooring.  
DO NOT INSTALL THIS WATER HEATER DIRECTLY ON A  
CARPETED FLOOR. A FIRE HAZARD MAY RESULT. Instead  
the water heater must be placed on a metal or wood panel  
extending beyond the full width and depth by at least 3 inches  
(76.2mm) in any direction. If the heater is installed in a carpeted  
alcove, the entire floor shall be covered by the panel. Also, see  
the DRAIN REQUIREMENTS.  
LOCATION  
When installing the heater, consideration must be given to proper  
location. Location selected should be as close to the stack or  
chimney as practicable with adequate air supply, and as  
centralized with piping system as possible.  
It is recommended that at least 24" (610mm) be provided on the  
left side and front of the unit for accessibility and proper servicing.  
In a utility room installation, the door shall be wide enough to  
allow the heater to enter or to permit the replacement of another  
appliance.  
THE HEATER SHOULD NOTBE LOCATED INANAREAWHERE  
IT WILL BE SUBJECT TO FREEZING.  
LOCATE IT NEAR A FLOOR DRAIN. THE HEATER SHOULD  
BE LOCATED IN AN AREA WHERE LEAKAGE FROM THE  
HEATER OR CONNECTIONS WILL NOT RESULT IN DAMAGE  
TO THE ADJACENT AREA OR TO LOWER FLOORS OF THE  
STRUCTURE.  
LEVELLING  
Each unit should be checked after installation to be certain that it  
is level.  
WHEN SUCH LOCATIONS CANNOT BEAVOIDED, ASUITABLE  
DRAIN PAN SHOULD BE INSTALLED UNDER THE HEATER.  
Such pans should be fabricated with sides at least 2" (50.8mm)  
deep, with length and width at least 2" (50.8mm) greater than the  
diameter of the heater and must be piped to an adequate drain.  
The pan must not restrict combustion air flow.  
If the unit is not level, obtain and insert metal shims under the  
base ring of the unit to correct this condition.  
AIR REQUIREMENTS  
Should the heater be installed in a garage, the heater must be  
located, or protected, so it is not subject to physical damage by a  
moving vehicle.  
WARNING  
FOR SAFE OPERATION AN AMPLE SUPPLY OF AIR MUST BE  
PROVIDED FOR PROPER COMBUSTIONAND VENTILATION.  
AN INSUFFICIENT SUPPLY OF AIR WILL RESULT IN A  
YELLOW/LUMINOUS BURNER FLAME, CAUSING CARBONING  
OR SOOTING OF THE FINNED HEAT EXCHANGER AND  
CREATING A RISK OF ASPHYXIATION. DO NOT OBSTRUCT  
THE FLOW OF COMBUSTION AND VENTILATION AIR.  
WARNING  
THERE IS A RISK IN USING FUEL BURNING APPLIANCES  
SUCH AS HEATERS IN ROOMS OR AREAS WHERE  
GASOLINE, OTHER FLAMMABLE LIQUIDS OR ENGINE  
DRIVEN EQUIPMENT OR VEHICLES ARE STORED,  
OPERATED OR REPAIRED. FLAMMABLE VAPORS ARE  
HEAVY AND TRAVEL ALONG THE FLOOR AND MAY BE  
IGNITED BY THE IGNITER OR MAIN BURNER FLAMES  
CAUSING FIRE OR EXPLOSION. SOME LOCAL CODES  
PERMIT OPERATION OF GAS APPLIANCES IN SUCH AREAS  
IF THEY ARE INSTALLED 18 INCHES OR MORE ABOVE THE  
FLOOR. THIS MAY REDUCE THE RISK IF LOCATION IN SUCH  
UNCONFINED SPACE  
In buildings of conventional frame, brick, or stone construction,  
unconfined spaces may provide adequate air for combustion,  
ventilation and draft hood dilution.  
AN AREA CANNOT BE AVOIDED.  
If the unconfined space is within a building of tight construction  
(buildings using the following construction: weather stripping,  
heavy insulation, caulking, vapor barrier, etc.), air for combustion,  
ventilation, and draft hood dilution must be obtained from outdoors.  
The installation instructions for confined spaces in tightly  
constructed buildings must be followed to ensure adequate air  
supply.  
WARNING  
FLAMMABLE ITEMS, PRESSURIZED CONTAINERS OR ANY  
OTHER POTENTIAL FIRE HAZARDOUS ARTICLES MUST  
NEVER BE PLACED ON OR ADJACENT TO THE HEATER.  
OPEN CONTAINERS OF FLAMMABLE MATERIAL SHOULD  
NOT BE STORED OR USED IN THE SAME ROOM WITH THE  
HEATER.  
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Do not install without draft hood and do not install any damper  
in flueway. Be sure that the vent pipe does not extend beyond  
the inside wall of the chimney.  
CONFINED SPACE  
When drawing combustion and dilution air from inside a  
conventionally constructed building to a confined space, such a  
space shall be provided with two permanent openings, ONE IN 2. Where a continuous or intermittent back draft is found to exist,  
OR WITHIN 12 INCHES (30.5cm) OF THE ENCLOSURE  
BOTTOM. Each opening shall have a free area of at least one  
square inch per 1000 Btuh (2,225mm2/Kw)of the total input of all  
appliances in the enclosure, but not less than 100 square inches  
(645 square cm).  
the cause must be determined and corrected. A special vent  
cap may be required.  
FAILURE TO CORRECT BACK DRAFTS MAY CAUSE AIR  
CONTAMINATION AND UNSAFE CONDITIONS.  
If the confined space is within a building of tight construction, air  
for combustion, ventilation and draft hood dilution must be  
obtained from outdoors. When directly communicating with the  
outdoors or communicating with the outdoors through vertical  
ducts, two permanent openings, located in the above manner,  
shall be provided. Each opening shall have a free area of not  
less than one square inch per 4000 Btuh (8,900mm2/Kw) of the  
total input of all appliances in the enclosure. If horizontal ducts  
are used, each opening shall have a free area of not less than  
one square inch per 2000 Btuh (4,450mm2/Kw) of the total input  
of all appliances in the enclosure. For Canadian installations  
consult CAN/CGA B149.  
If the back draft cannot be corrected by the normal methods  
or if a suitable draft cannot be obtained, ablower type flue  
gas exhauster must be employed to assure proper venting  
and correct combustion.  
3. Do not connect the heater to a common flue or chimney with  
solid fuel burning equipment. This practice is prohibited by  
many local building codes as is the practice of venting gas  
fired equipment to the duct work of ventilation systems.  
Where a separate vent connection is not available and the  
vent pipe from the heater must be connected to a common  
flue with an oil burning furnace, the vent pipe should enter the  
common flue or chimney at a point above the flue pipe from oil  
furnace.  
Where an exhaust fan is installed in the same room with a heater,  
sufficient openings for air must be provided in the walls.  
UNDERSIZED OPENINGS WILL CAUSE AIR TO BE DRAWN  
INTO THE ROOM THROUGH THE CHIMNEY, CAUSING POOR  
COMBUSTION. SOOTING MAY RESULT AND RISK OF  
ASPHYXIATION WILL OCCUR.  
4. Where two or more appliances vent into a common vent  
connector or manifold, the area of the common vent should at  
least equal the area of the largest flue or vent connector plus  
50% of the areas of the additional draft hood outlets.  
VENTING  
5. Refer to the National Fuel Gas Code for information pertaining  
to multiple heater venting. The ASHRAE HVAC SYSTEMS &  
EQUIPMENT HANDBOOK 2000, as well as many  
manufacturers’ gas vent and chimney sizing handbooks  
contain information on multiple heater manifold venting.  
WARNING  
THE INSTRUCTIONS IN THIS SECTION ON VENTING THE  
HEATER MUST BE FOLLOWED TO AVOID CHOKED  
COMBUSTION OR RECIRCULATION OF FLUE GASES. SUCH  
CONDITIONS CAUSE SOOTING OR RISKS OF FIRE AND  
ASPHYXIATION.  
RELIEF VALVE  
An ASME-rated pressure relief valve (Supplied) must be installed  
in the hot water outlet line as near to the heater as possible. This  
pressure relief valve is rated in accordance with and comply with  
the ANSI/ASME Boiler and Pressure Vessel Code, Section IV  
(“Heating Boilers”), 1989 edition (or latest edition).  
In the United States:  
Vent sizing, installation and termination shall be in accordance  
with the NATIONAL FUELGAS CODE.ANSI Z223.1-1999 or most  
recent edition.  
In Canada:  
A C.S.A design-certified and ASME-rated temperature and  
pressure relief valve (Not Supplied) must be installed on each  
and every water storage tank. This relief valve shall comply with  
the Standard for Relief Valves andAutomatic Gas Shutoff Devices  
for Hot Water Supply systems, “ANSI Z21.22-1986 or latest  
edition”. This relief valve should have a temperature rating of  
2100F (98.8°C), a pressure rating not exceeding the lowest rated  
working pressure of any system component and a discharge  
capacity exceeding the total input of the water heaters supplying  
water to the storage tank.  
With Canadian Installation Code CAN/CGA B149 (latest edition)  
Type B venting may be used with these heaters. All local and  
utility regulations on venting should be followed.  
Remove all soot or other obstructions from chimney which will  
retard free draft.  
1. Install and size the vent pipe as necessary. The connection  
from the heater to the chimney should be run full size and  
should have a minimum pitch upward to the chimney of one  
quarter inch per foot length.  
Select a relief valve with a discharge capacity exceeding the  
maximum heater input rating and a pressure rating not exceeding  
the working pressure shown on the rating plate of the heater.  
Locate the T & P relief valve in the top of the tank, or in the side of  
the tank on centerline within the upper 6 inches from the top of  
the tank. See installation diagrams. Tapping shall be threaded in  
accordance with the latest version of the Standard for Pipe  
Threads, General Purpose (inch), ANSI/ASME B1.20.1. Mark  
location with a Class III label. See ANSI Z21.10.1, Part 1,  
MARKING.  
PROPER VENT PIPE INSTALLATION  
FIGURE 6  
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Your local code authority may have other specific relief valve  
requirements not covered in this section.  
WATER LINE CONNECTIONS  
This manual provides detailed installation diagrams for typical  
methods of application. See piping diagrams.  
THE PURPOSE OF A RELIEF VALVE IS TOAVOID EXCESSIVE  
PRESSURE OR TEMPERATURE INTO THE STEAM RANGE,  
WHICH MAY CAUSE SCALDING AT FIXTURES, TANK  
EXPLOSION, SYSTEM OR HEATER DAMAGE.  
Cer-Temp 80 Recovery System (for one temperature water).  
These diagrams will serve to provide the installer with a reference  
for the materials and method of piping necessary for installation.  
It is essential that all water and gas piping, vent connections,  
electrical wiring and check and flow regulating valves be installed  
as shown on the diagrams.  
TO AVOID SCALDING OR WATER DAMAGE, A DRAIN LINE  
MUST BE CONNECTED TO A RELIEF VALVE TO DIRECT  
DISCHARGE TO A SAFE LOCATION. A DRAIN LINE MUST  
NOT BE REDUCED FROM THE SIZE OF THE VALVE OUTLET  
AND IT MUST NOT CONTAIN ANY VALVES BETWEEN THE  
HEATERAND THE RELIEF VALVE OR THE RELIEF VALVEAND  
THE DRAIN LINE EXIT. IN ADDITION, THERE SHOULD NOT  
BE ANY RESTRICTIONS IN A DRAIN LINE NOR SHOULD IT  
BE ROUTED THROUGH AREAS WHERE FREEZING  
CONDITIONS MIGHT OCCUR. DO NOT THREAD OR CAP THE  
DRAIN LINE EXIT. RESTRICTING OR BLOCKING A DRAIN  
LINE WILL DEFEAT THE PURPOSE OF THE RELIEF VALVE  
AND MAY CREATE AN UNSAFE CONDITION. INSTALL A  
DRAIN LINE WITH A DOWNWARD SLOPE SUCH THAT IT  
NATURALLY DRAINS ITSELF.  
Consult the installation diagrams for appropriate locations to  
install the safety flow switch(es), drain valves, thermometers,  
relief valves and the circulating pump(s). Apply suitable pipe  
thread sealing compounds to only the male threads of parts to  
be connected. If any of these parts are being replaced in a  
functioning system, remember to shut off the manual gas and  
control valve(s) and close off the water inlet(s). Open a nearby  
faucet to relieve pressure and drain the heater and/or system  
before attempting to install the new parts.  
Recommended locations of relief valves are shown in the  
installation diagrams.  
Check the diagrams thoroughly before starting installation to  
avoid errors and minimize time and material costs.  
HARD WATER  
If the system is to be filled with water for testing or other  
purposes during cold weather and before actual operation, care  
must be taken to prevent a downdraft entering the heater or  
freezing air from contacting the system. Failure to do so may  
cause the water in the system to freeze with resulting damage  
to the system. Damage due to freezing is not covered by the  
warranty.  
Where hard water conditions exist, water softening or the threshold  
type of water treatment is recommended. This will protect the  
dishwashers, coffee urns, water heaters, water piping and other  
equipment. When water softening or water treatment is not  
practical, a comparatively easy method of periodic lime removal  
from the heater may be employed by installing gate valves, drain  
valve and acid fill opening as shown in PREVENTIVE  
MAINTENANCE section of this manual.  
WATER (POTABLE) HEATING  
CLOSED WATER SYSTEM  
1. All piping components connected to this unit for space  
heating applications shall be suitable for use with potable  
water.  
A closed system will exist if a back-flow prevention device (check  
valve), pressure reducing valve, or other similar device is installed  
in the cold water line between the water heater and the street  
main (or well). Excessive pressure may develop due to the  
thermal expansion of heated water causing premature tank  
failure or intermittent relief valve operation. This is not a warranty  
failure. An expansion tank may be necessary in the cold water  
supply to alleviate this situation. Contact the local plumbing  
authority.  
2. Toxic chemicals, such as those used for boiler treatment,  
shall NEVER be introduced into this system.  
3. This unit may NEVER be connected to any existing heating  
system or component(s) previously used with a non-potable  
water heating appliance.  
10  
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