American Water Heater 74 Gallon 75100 BTU UltraLow Nox High Recovery Natural Gas Water Heater UBG6275T75S4NV user manual

							1
PRINTED IN U.S.A. 1112 PART NO. 325321-000
PLACE THESE INSTRUCTIONS ADJACENT TO HEATER
AND NOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.
RESIDENTIAL ULTRA LOW NOx GAS WATER HEATER
•  INSTALLATION   •   OPERATION   •   SERVICE   •   MAINTENANCE  • 
  CAUTION
TEXT PRINTED OR OUTLINED IN RED CONTAINS INFORMATION 
RELATIVE TO YOUR SAFETY. PLEASE READ THOROUGHLY 
BEFORE INSTALLING AND USING THIS APPLIANCE.
LOW LEAD
CONTENT 
						

							2
FOREWORD
The design of these models comply with the current edition of ANSI 
Z21.10.3/CSA 4.3 an automatic storage water heater.
Installation diagrams are found in this manual.  These diagrams will serve 
to provide the installer with a reference for the materials and method of 
piping necessary.  It is highly essential that all water and gas piping be 
installed as shown on the diagrams.
In addition to these instructions, the equipment 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.
The installation must conform with these instructions and the local code 
authority having jurisdiction. In the absence of local codes, installations 
should comply with the National Fuel Gas Code (ANSI Z223.1/NFPA 
ROUGH-IN DIMENSIONS
FIGURE 1.
54) and the National Electric Code (NFPA 70). These publications are 
available from The National Fire Protection Association, 1 Batterymarch 
Park, Quincy, MA 02269 
Thank You for purchasing this water heater. Properly installed and 
maintained, it should give you years of trouble free service.
Abbreviations Found In This Manual:
• CSA-Canadian Standards Association
•  ANSI-American National Standards Institute
•  NFPA-National Fire Protection Association
•  AHRI-Air Conditioning, Heating and Refrigeration Institute
• UL-Underwriters Laboratories
This gas-fired water heater is design certified by Underwriters 
Laboratories Inc. under American National Standard/CSA Standard for 
Gas Wtare Heaters ANSI Z21.10.3•CSA 4.3 (current edition).
*INSTALL IN ACCORDANCE WITH LOCAL CODES
TOP VIEW
TABLE 3, GAS AND ELECTRICAL CHARACTERISTICS
All Models:  Maximum supply pressure = 14.0 in. W.C. (3.48 kPa)
  Minimum supply pressure, Natural gas = 6 in. W.C. (1.49 kPa). 
  Minimum pressures must be maintained under both load and no load (static and dynamic) conditions.
TABLE 1, DIMENSIONS
INPUT RATE Recovery in US Gallons/hr or Liters/hr at Indicated Temperature Rise in Fahrenheit or Celsius
75,100  BTU/H°F 30 36 40 50 54 60 70 72 80 90 100 108 110 120 126 130 140
GPH243 203 182 145 134 122 104 101 91 81 73 67 66 60 57 56 52
    22       KW°C 17 20 23 28 30 33 39 40 44 50 56 60 61 67 70 72 78
LPH920 767 688 549 509 460 392 381 344 306 277 254 251 228 217 213 199
Units A B C D E F G H J K L M P Q
Inches
CM66 5/8
169.2258 3/4
149.2330 15/16
76.9927 3/4
70.515 1/4
38.64
10.215 3/4
40.016
40.61 1/4
3.21 1/4
NPT1/2
NPT12 1/4
31.124 7/8
63.253 7/8
136.8
TABLE 2, RECOVERY RATINGS ARE BASED ON 80% THERMAL EFFICIENCY 
Manifold Pressure Electrical Characteristics
Type of gas Inches W.C. kPa Voltz/Hz Amperes
Natural Gas 4.0 1.12 120/60 
						

							3
GENERAL SAFETY 
						

							4
GENERAL SAFETY 
INFORMATION
PRECAUTIONS
DO NOT USE THIS WATER HEATER IF ANY PART HAS BEEN UNDER 
WATER. Immediately call a qualifi ed service technician to inspect the 
water heater and to replace any part of the control system and any gas 
control which has been under water.
IF THE UNIT IS EXPOSED TO THE FOLLOWING, DO NOT OPERATE 
HEATER UNTIL ALL CORRECTIVE STEPS HAVE BEEN MADE BY A 
QUALIFIED SERVICEMAN.
1. EXTERNAL FIRE.
2. DAMAGE.
3.  FIRING WITHOUT WATER.
4. SOOTING.
Heater must be protected from freezing downdrafts during shutdown periods.
PREPARING FOR THE INSTALLATION
1.  Read the “General Safety” section, page 3 of this manual fi rst  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, 
SERIOUS BODILY INJURY AND/OR PROPERTY DAMAGE.
  This manual contains instructions for the installation, operation, and 
maintenance of the gas-fi red 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 fi rst few 
pages, READ THE ENTIRE MANUAL BEFORE ATTEMPTING TO 
INSTALL OR OPERATE THE WATER HEATER.
2.   The installation must conform with these instructions and the local 
code authority having jurisdiction. In the absence of local codes, 
installations shall comply with the National Fuel Gas Code ANSI 
Z223.1/NFPA 54 current addition. This publication is available from 
the CSA International, 8501 East Pleasant Valley Rd., Cleveland 
Ohio 44131, or The National Fire Protection Association, 1 
Batterymarch Park, Quincy, MA 02269. 
TABLE OF CONTENTS
                                                                                                                 PageROUGH-IN DIMENSIONS .............................................................  2
FOREWORD .................................................................................   2
GENERAL SAFETY INFORMATION
 Precautions ................................................................................  4
  Preparing for the Installation ......................................................   4
 Grounding Instructions...............................................................  4
  Chemical Vapor Corrosion .........................................................   5
  Extended Non-use Periods ........................................................   5
 Insulation Blankets.....................................................................  5
 High Altitude Installations...........................................................  5
 Circulating Pump .......................................................................  6
INSTALLATION INSTRUCTIONS
 Required Ability ..........................................................................  6
 Locating The Heater ..................................................................  6
 Clearances.................................................................................  6
 Hard Water ................................................................................  6
 Air Requirements .......................................................................  6-7 
 Unconfi ned Space .....................................................................   7
 Confi ned Space .........................................................................   7
 Venting .......................................................................................  7-8
 Vent Connection ........................................................................  8
 Thermometers ...........................................................................  8
  Combination Water (Potable) and Space Heating .....................   8
 Mixing Valves .............................................................................  8 
 System Connections ..................................................................  9
 Relief Valve ...............................................................................  9 Gas Piping ................................................................................  9
 Purging .....................................................................................  10
  Gas Meter Size .........................................................................   10
  Gas Pressure Regulator ...........................................................   10
OPERATION .................................................................................  10
  To Operate The Heater .............................................................   10
 Heater Wiring ............................................................................  11
 Lighting Instructions ..................................................................  12
 Temperature Regulation ...........................................................  13
 Checking Venting ......................................................................  13
  HIgh Temperature Limit Switch .................................................   13
SERVICE INFORMATION ............................................................  14-15
  Main Burner and Igniter ............................................................   14
  Checking Gas Input ..................................................................   14
 Vent System..............................................................................  14
 Blower Maintenance .................................................................  15
 Relief Valve ...............................................................................  15
  Hot Water Odor .........................................................................   15
 Winter Protection ......................................................................  15
 Replacement Parts ...................................................................  15
  Draining and Flushing ...............................................................   15
CHECKLIST .................................................................................  15-16
 Condensation............................................................................  16
  Anode Rod Inspection ..............................................................   16
  Service and Repair ...................................................................   16
TROUBLESHOOTING .................................................................  17-19
3.   If after reading this manual you have any questions or do not 
understand any portion of the instructions, call the local gas utility 
or the manufacturer whose name appears on the rating plate.
4.    Carefully plan the place where you are going to put the water heater.  
Correct  combustion, vent action, and vent pipe installation are 
very important in preventing death from possible carbon monoxide 
poisoning and fi res, see Figures 3 through 8A.
  Examine the location to ensure the water heater complies with the 
“Locating the New Water Heater” 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 Offi ce of the State Architect, 400 P Street, 
Sacramento, CA 95814.
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.
7.    Complies with SCAQMD rule #1146.2 and districts having equivalent 
NOx requirements.
GROUNDING INSTRUCTIONS
This water heater must be grounded in accordance with the National 
Electrical 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, see Figure 5.
 Page 
						

							5
CHEMICAL VAPOR CORROSION
 WARNINGCORROSION 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.
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.)
EXTENDED NON-USE PERIODS
 WARNINGHYDROGEN GAS CAN BE PRODUCED IN A HOT WATER SYSTEM 
SERVED BY THIS HEATER THAT HAS NOT BEEN USED FOR A LONG 
PERIOD OF TIME (GENERALLY TWO WEEKS OR MORE). HYDROGEN 
GAS IS EXTREMELY FLAMMABLE. 
 To reduce the risk of injury under 
these conditions, it is recommended that the hot water faucet be opened 
for several minutes at the kitchen sink before using any electrical water 
heater connected to the hot water system.  If hydrogen is present, there 
will probably be an unusual sound such as air escaping through the pipe 
as the water begins to fl ow.   
THERE SHOULD BE NO SMOKING OR 
OPEN FLAME NEAR THE FAUCET AT THE TIME IT IS OPEN.
INSULATION BLANKETS
Insulation blankets available to the general public for external use on gas 
water heaters are not required for use on this water heater. The purpose 
of an insulation blanket is to reduce the standby heat loss encountered 
with storage tank water heaters. This water heater meets or exceeds the 
current edition of ASHRAE/IES 90.1 standards with respect to insulation 
and standby loss requirement making an insulation blanket unnecessary.
  WARNING
Should you choose to apply an insulation blanket to this heater, you 
should follow these instructions.  Failure to follow these instructions can 
result in fi re, asphyxiation , serious personal injury or death.
•  Do not apply insulation to the top of the water heater, as this will 
interfere with safe operation.
•  Do not cover the outer door, thermostat or temperature & pressure 
relief valve.
•  Do not allow insulation to come within 2 (5cm) of the fl oor to prevent 
blockage of combustion air fl ow to the burner.
•  Do not cover the instruction manual.  Keep it on the side of the water 
heater or nearby for future reference.
•  Do obtain new warning and instruction labels from manufacturer for 
placement on the blanket directly over the existing labels.
•  Do inspect the insulation blanket frequently to make certain it does 
not sag, thereby obstructing combustion air fl ow.
HIGH ALTITUDE INSTALLATIONS
Water heaters covered in this manual have been tested and approved for 
installation at elevations up to 7,700 feet (2,347 m) above sea level. For 
installation above 7,700 feet (2,347 m), the water heater’s Btu input should 
be reduced at the rate of 4 percent for each 1,000 feet (305 m) above sea 
level which requires replacement of the burner orifi ce in accordance with 
the National Fuel Gas Code ANSI Z223.1/NFPA 54. Contact your local 
gas supplier for further information.
Failure to replace the standard orifi ce with the proper high altitude orifi ce 
when installed at elevations above 7,700 feet (2,347 m) could result in 
improper and ineffi cient operation of the water heater, producing carbon 
monoxide gas in excess of the safe limits. This could result in serious 
injury or death. Contact your local gas supplier for any specifi c changes 
that may be required in your area.
The input reduction is primarily achieved by reducing the size of the main 
burner orifi ces.  To do this, the main burner orifi ces require replacement 
with orifi ces sized for the particular installation elevation.  Correct orifi ce 
sizing and parts may be obtained from your distributor or manufacturer.  
When ordering, be sure to state the model number and the altitude of 
the location where the water heater is being installed.
Upon completion of derating of the heater, adjustment to the gas pressure 
regulator may be required.  See CHECKING THE GAS INPUT section 
in this manual for inlet and manifold pressure requirements.
Also due to the input rating reduction required at high altitudes, the output 
rating of the water heater is also reduced and should be compensated 
for in the sizing of the equipment for application. 
						

							6
CIRCULATING PUMP
A circulating pump is used when a system requires a circulating loop or 
there is a storage tank used in conjunction with the heater.  Refer to the 
piping diagrams at rear of manual for electrical hookup information and 
install in accordance with the current edition of the National Electrical 
Code ANSI/NFPA No. 70.
Only all bronze circulating pumps are used with commercial water 
heaters. Although circulators are oiled and operated by the manufacturer 
some circulators must be oiled again before operating.  Please refer to 
manufacturer’s instructions. 
INSTALLATION INSTRUCTIONS
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, ELECTRICAL 
AND GAS SUPPLY WORK ARE REQUIRED.
LOCATING THE HEATER
  WARNING
THERE IS A RISK IN USING FUEL BURNING APPLIANCES SUCH AS 
GAS WATER HEATERS IN ROOMS, GARAGES OR OTHER 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 HEATER’S 
PILOT OR MAIN BURNER FLAMES CAUSING FIRE OR EXPLOSION.
 
SOME LOCAL CODES PERMIT OPERATION OF GAS APPLIANCES 
IF INSTALLED 18 INCHES (45.7 CM) OR MORE ABOVE THE FLOOR. 
THIS MAY REDUCE THE RISK IF LOCATION IN SUCH AN AREA 
CANNOT BE AVOIDED.
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 (7.6 cm) in any direction.  If the heater is 
installed in a carpeted alcove or closet, the entire fl oor shall be covered 
by the panel.  Also, see the drain requirements.
THE WATER SUPPLY PRESSURE SHOULD NOT EXCEED 80 PSI 
(551.58 kPa). IF THIS OCCURS, A PRESSURE REDUCING VALVE 
WITH A BYPASS SHOULD BE PLACED ON THE SUPPLY TO THE 
ENTIRE HOUSE IN ORDER TO MAINTAIN EQUAL HOT AND COLD 
WATER PRESSURES.
THIS HEATER SHALL BE LOCATED OR PROTECTED SO IT IS NOT 
SUBJECT TO PHYSICAL DAMAGE BY A MOVING VEHICLE.
  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.
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 the 
piping system as possible.
THE HEATER MUST NOT BE LOCATED IN AN AREA WHERE IT WILL 
BE SUBJECT TO FREEZING.
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.
WHEN SUCH LOCATIONS CANNOT BE AVOIDED, A SUITABLE 
DRAIN PAN SHOULD BE INSTALLED UNDER THE HEATER.  Such 
pans should be fabricated with sides at least 2 (5cm) deep, with length 
and width at least 2 (5cm) greater than the diameter of the heater 
and must be piped to an adequate drain.  The pan must not restrict 
combustion air fl ow.
Drain pans suitable for these heaters are available from your distributor 
or Water Heater Parts Fulfi llment, 125 Southeast Parkway, Franklin, 
TN 37068.
For appliance installation locations with elevations above 7700 feet 
(610 meters), refer to HIGH ALTITUDE INSTALLATIONS section of this 
manual for input reduction procedure.
CLEARANCES
These heaters are approved  for installation on combustible fl ooring in a 
closet having a ceiling 12 (30.5cm) above top cover and with clearances 
to combustible construction of 6 (15.2cm) from fl ue or vent connector, 0 
(0cm) at the sides and rear and 5 (10.2cm) to front to prevent a possible 
fi re hazard condition.  A minimum of 4 (10.2cm) shall be allowed for 
installation of serviceable parts.
HARD WATER
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.
See MAINTENANCE section for details of tank cleanout procedure.
AIR REQUIREMENTS
REFER TO THE CURRENT EDITION OF THE NATIONAL FUEL GAS 
CODE ANSI Z223.1/NFPA 54.
KEEP APPLIANCE AREA CLEAR AND FREE OF COMBUSTIBLE 
MATERIALS, GASOLINE AND OTHER FLAMMABLES, VAPORS AND 
LIQUIDS.
DO NOT OBSTRUCT THE FLOW OF COMBUSTION OR VENTILATING 
AIR.
 WARNING
ATTIC AND/OR EXHAUST FANS OPERATING ON THE PREMISES 
WITH A WATER HEATER CAN RESULT IN CARBON MONOXIDE 
POISONING AND  DEATH.
OPERATION OF THESE FANS CAN PRODUCE A NEGATIVE DRAFT IN 
THE AREA OF THE WATER HEATER PREVENTING THE PRODUCTS 
OF COMBUSTION FROM EXHAUSTING THROUGH THE CHIMNEY 
OR VENT PIPE.
The venting of the water heater should be inspected by a qualifi ed service 
technician at the time of installation and periodically thereafter to ensure 
a down-draft condition does not exist.
 WARNING
FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR COMBUSTION 
AND VENTILATION. AN INSUFFICIENT SUPPLY OF AIR WILL CAUSE 
RECIRCULATION OF COMBUSTION PRODUCTS RESULTING IN 
AIR CONTAMINATION THAT MAY BE HAZARDOUS TO LIFE. SUCH 
A CONDITION OFTEN WILL RESULT IN A YELLOW, LUMINOUS 
BURNER FLAME, CAUSING CARBONING OR SOOTING OF THE 
COMBUSTION CHAMBER, BURNERS AND FLUE TUBES AND 
CREATES A RISK OF ASPHYXIATION. 
						

							7
CAUTION: IF BUILDING COLD WATER SUPPLY HAS A BACK-FLOW
PREVENTER, CHECK VALVE OR WATER METER WITH CHECK 
VALVE, AN EXPANSION TANK MUST BE PROVIDED.
FIGURE 2.
CIRCULATING RETURN LINE CONNECTIONS
TEMPERED WATER LOOP, IF USED, CONNECT TO POINT A.  
STORED TEMPERATURE WATER LOOP, IF USED, CONNECT TO 
COLD WATER INLETWARNING
TEMPERATURE SETTING SHOULD NOT EXCEED SAFE 
USE TEMPERATURE AT FIXTURES.  SEE TEMPERATURE 
REGULATION ON PAGE 11.  IF HIGHER PREHEAT 
TEMPERATURES ARE NECESSARY TO OBTAIN 
ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD 
VALVE FOR HOT WATER SUPPLIED TO FIXTURES.
SINGLE TEMPERATURE
Where an exhaust fan is supplied in the same room with a heater, 
suffi cient 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 IN SERIOUS DAMAGE TO THE HEATER 
AND RISK OF FIRE OR EXPLOSION.
DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND VENTILATING 
AIR.  ADEQUATE AIR FOR COMBUSTION AND VENTILATION MUST 
BE PROVIDED FOR SAFE OPERATION.
UNCONFINED SPACE
In buildings of conventional frame, brick, or stone construction, 
unconfi ned spaces may provide adequate air for combustion, ventilation 
and draft hood dilution.
If the unconfi ned 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 confi ned spaces in tightly constructed buildings must be followed to 
ensure adequate air supply.
CONFINED SPACE
When drawing combustion and dilution air from inside a conventionally 
constructed building to a confi ned space, such a space shall be provided 
with two permanent openings, ONE IN OR WITHIN 12 INCHES (30.5cm) 
OF THE ENCLOSURE TOP AND ONE IN 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 (2,225mm
2/Kw) of 
the total input of all appliances in the enclosure, but not less than 100 
square inches (645 square cm).If the confi ned 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 
(8,900mm
2/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 (4,450mm
2/Kw) of the total 
input of all appliances in the enclosure.
VENTING
 WARNING
THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE 
FOLLOWED TO AVOID CHOKED COMBUSTION OR RECIRCULATION 
OF FLUE GASES.  SUCH CONDITIONS CAUSE SOOTING OR RISKS 
OF  FIRE AND ASPHYXIATION.
This water heater must be protected from freezing downdrafts.
Remove all soot or other obstructions from the chimney that will retard 
a free draft.
Type B venting is recommended with these water heaters.
This water heater must be vented in compliance with all local codes, the 
current edition of the National Fuel Gas Code, ANSI Z223.1/NFPA 54, 
and with the Category I Venting Table.
If any part of the vent system are exposed to ambient temperatures below 
35 degrees F (2 degrees C) it must be insulated to prevent condensation.
•  Do not connect the heater to a common vent or chimney with solid 
MIXING VALVE APPLICATION FOR TWO TEMPERATURE WATER
VACUUM RELIEF
       VALVE
*INSTALL PER 
LOCAL CODES. 
						

							8 fuel burning equipment.  This practice is prohibited by many local  
building codes as is the practice of venting gas fi red 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 vent with an 
oil burning furnace, the vent pipe should enter the smaller common 
vent or chimney at a point above the large vent pipe.
FIGURE 3.
VENT CONNECTION
Vent connections must be made to an adequate stack or chimney. Size 
and install proper size vent pipe.  Do not reduce pipe size to less than 
that of the blower outlet.
Horizontal runs of vent pipe must have a minimum upward slope 
toward the chimney of 1/4 inch per foot (2cm per meter).  Dampers or 
other obstructions must not be installed in between the heater and the 
blower.  Be sure that the vent pipe does not extend beyond the inside 
wall of the chimney.
Where a continuous or intermittent back draft is found to exist, the 
cause must be determined and corrected.  A special vent cap may be 
required.  If the back draft cannot be corrected by the normal methods or 
if a suitable draft cannot be obtained, a blower type fl ue gas exhauster 
must be employed to assure proper venting and correct combustion.
THERMOMETERS (Not Supplied)
Thermometers should be obtained and fi eld installed as shown in Figure 3.
Thermometers are installed in the system as a means of detecting the 
temperature of the outlet water supply.
COMBINATION WATER (POTABLE) HEATING 
AND SPACE HEATING
1.  All piping components connected to this unit for space heating 
applications shall be suitable for use with potable water.
2.   These water heaters connot be used in space heating applications 
only.
3.  Toxic chemicals, such as those used for boiler treatment, shall 
NEVER be introduced into this system.
4.  This unit may NEVER be connected to any existing heating system 
or component(s) previously used with a non-potable water heating 
appliance.
5.  When the system requires water for space heating at temperatures 
higher than required for domestic water purposes, a tempering valve 
must be installed.  Please refer to installation diagram on page 6 of  
this manual for suggested piping arrangements.
 CAUTION
A closed system will exist if a check valve (without bypass), pressure 
reducing valve (without bypass), or a water meter (without bypass) is 
installed in the cold water line between the water heater and street 
main (or well).
Excessive pressure may develop in such closed systems, causing 
premature tank failure or intermittent relief valve operation.  This is not a 
warranty failure.  An expansion tank or a similar device may be required 
in the inlet supply line between the appliance and the meter or valve to 
compensate for the thermal expansion of the water.
As water is heated, it expands (thermal expansion). In a closed system, the 
volume of water will increase. As the volume of water increases, there will 
be a corresponding increase in water pressure due to thermal expansion. 
Thermal expansion can cause premature tank failure (leakage). This type 
of failure is not covered under the limited warranty. Thermal expansion 
can also cause intermittent temperature-pressure relief valve operation: 
water discharged from the valve due to excessive pressure build up. The 
temperature-pressure relief valve is not intended for the constant relief 
of thermal expansion. This condition is not covered under the limited 
warranty.
A properly-sized thermal expansion tank should be installed on all closed 
systems to control the harmful effects of thermal expansion. Contact a 
plumbing service agency or your retail supplier reguarding the installation 
of a thermal expansion tank.
MIXING VALVES
DANGERWater temperature  over 125°F (52°C)
can cause severe burns instantly
resulting in severe injury or death.
Children, the elderly and the physically 
or mentally disabled are at highest risk 
for scald injury.
Feel water before bathing or showering.
Temperature limiting devices such as 
mixing valves must be installed when 
required by codes and to ensure safe 
temperatures at fixtures.
Water heated to a temperature which will satisfy clothes washing, dish 
washing, and other sanitizing needs can scald and cause permanent 
injury upon contact. Short repeated heating cycles caused by small hot 
water uses can cause temperatures at the point of use to exceed the 
water heater’s temperature setting by up to 20°F (11°C).
Some people are more likely to be permanently injured by hot water than 
others. These include the elderly, children, the infi rm and the physically/
mentally disabled. Table 1 shows the approximate time-to-burn 
relationship for normal adult skin. If anyone using hot water provided by 
the water heater being installed fi ts into one of these groups or if there 
is a local code or state law requiring a certain water temperature at the 
point of use, then special precautions must be taken.
In addition to
 using lowest possible temperature setting that satisfi es demand of 
application a Mixing Valve should be installed at water heater (see Figure 3) 
or at hot water taps to further reduce system water temperature.
Mixing valves are available at plumbing supply stores. Consult a Qualifi ed 
Installer or Service Agency. Follow mixing valve manufacturer’s instructions 
for installation of the valves. 
						

							9
TABLE 4. GAS SUPPLY LINE SIZES (IN INCHES)*
Water Temperature °FTime for 1st Degree Burns
(Less Severe Burns)Time for Permanent Burns
2nd & 3rd Degree
(Most Severe Burns)
110 (normal shower temp.)
116 (pain threshold)
116 35 minutes 45 minutes
122 1 minute 5 minutes
131 5 seconds 25 seconds
140 2 seconds 5 seconds
149 1 second 2 seconds
154 instantaneous 1 seconds
(U.S. Government Memorandum, C.P.S.C., Peter L. Armstrong, Sept. 15, 1978)
HOT WATER
OUTLET
TO TANK
INLET CHECK
VA LV EMIXING
VA LV E COLD
WATER
INLETTEMPERED WATER
OUTLET
12” TO 15”
(30-38 cm)
CHECK
VA LV E
  FIGURE 4.
SYSTEM CONNECTIONS
The system installation must conform to these instructions and to the 
local code authority having jurisdiction.  Good practice requires that all 
heavy piping be supported.
RELIEF VALVE
This water heater is equipped with a combination temperature-pressure 
relief valve that complies with the standard for relief valves for hot water 
supply systems Z21.22-CSA 4.4. 
FOR SAFE OPERATION OF THE 
WATER HEATER, THE RELIEF VALVE(S) MUST NOT BE REMOVED 
OR PLUGGED.
ASME ratings cover pressure relief capacities. ANSI ratings cover release 
rate with temperature actuation.
In addition to the water heater relief valve, each remote storage tank 
which may be used in conjunction with this appliance shall also be 
installed with a properly sized, rated and approved combination 
temperature (ANSI) and pressure (ASME) relief valve(s). This valve 
shall comply with the standard for relief valves for hot water supply 
systems Z21.22-CSA 4.4.
 WARNING
THE PURPOSE OF RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE 
OR TEMPERATURE INTO THE STEAM RANGE, WHICH MAY CAUSE 
SCALDING  AT FIXTURES, TANK EXPLOSION, SYSTEM OR HEATER 
DAMAGE.  NO VALVE IS TO BE PLACED BETWEEN THE 
RELIEF 
VALVE AND TANK.
Your local code authority may have other specifi  c relief valve requirements.
A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO 
DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING OR 
WATER DAMAGE.  THIS LINE MUST NOT BE REDUCED FROM THE 
SIZE OF THE VALVE OUTLET AND MUST NOT CONTAIN VALVES, 
RESTRICTIONS NOR SHOULD IT BE LOCATED IN FREEZING AREAS.  
DO NOT THREAD OR CAP THE END OF THIS LINE.  RESTRICTED OR 
BLOCKED DISCHARGE WILL DEFEAT THE PURPOSE OF THE VALVE 
AND IS UNSAFE.  DISCHARGE LINE SHALL BE INSTALLED TO ALLOW 
COMPLETE DRAINAGE OF BOTH THE VALVE AND LINE.
See SERVICE INFORMATION section for procedure and precautions.
The type, size and location of the relief valves must be in accordance 
with local codes.  The location of the relief valve is shown in Figure 1.  
The heater has a factory installed high temperature limit switch.
GAS PIPING
Contact your local gas service company to ensure that adequate gas service 
is available and to review applicable installation codes for your area.
Size the main gas line in accordance with Table 4. The fi gures  shown 
are for straight lengths of pipe at 0.5 W.C. (.125 kPa) pressure drop, 
which is considered normal for low pressure systems.  Note:  Fittings 
such as elbows, tees and line regulators will add to the pipe pressure 
drop.  Also refer to the current edition of the National Fuel Gas Code.
 WARNING
The minimum gas supply pressure for input adjustment is 6.0 W.C.(1.49 
kPa) for natural gas.
THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER THAN 
14 W.C. (3.49 kPa) SUPPLY PRESSURE. EXPOSURE TO HIGHER GAS 
SUPPLY PRESSURE MAY CAUSE DAMAGE TO THE CONTROL WHICH 
COULD RESULT IN FIRE OF EXPLOSION. 
If overpressure has occurred 
such as through improper testing of gas lines or emergency malfunction 
of the supply system, the control must be checked for safe operation. 
Make sure that the outside vents on the supply regulators and the safety 
vent valves are protected against blockage. These are parts of the gas 
supply system not the heater. Vent blockage may occur during ice storms.
IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING FROM 
CONTAMINANTS IN THE GAS WAYS.  SUCH FOULING MAY CAUSE 
IMPROPER OPERATION, FIRE OR EXPLOSION.
IF COPPER SUPPLY LINES ARE USED THEY MUST BE INTERNALLY 
TINNED AND CERTIFIED FOR GAS SERVICE. BEFORE ATTACHING THE 
GAS LINE, BE SURE THAT ALL GAS PIPE IS CLEAN ON THE INSIDE.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS SUPPLY 
LINE, A SEDIMENT TRAP MUST BE INCORPORATED IN THE PIPING 
(SEE FIG. 5).  THE SEDIMENT TRAP MUST BE READILY ACCESSIBLE 
AND NOT SUBJECT TO FREEZING CONDITIONS. INSTALL IN 
ACCORDANCE WITH RECOMMENDATIONS OF SERVING GAS 
SUPPLIERS.  REFER TO THE CURRENT EDITION OF THE NATIONAL 
FUEL GAS CODE. 
To prevent damage, care must be taken not to apply too much torque 
when attaching gas supply pipe to gas valve inlet.
Apply joint compounds (pipe dope) sparingly and only to the male threads 
of pipe joints.  Do not apply compounds to the fi rst two threads.  Use 
compounds resistant to the action of liquefi ed petroleum gases. 
						

							10
PURGING
Gas line purging is required with new piping or systems in which air has 
entered.
  CAUTIONPURGING SHOULD BE PERFORMED BY PERSONS EXPERIENCED 
IN THIS TYPE GAS SERVICE. TO AVOID RISK OF FIRE OR 
EXPLOSION, PURGE DISCHARGE MUST NOT ENTER CONFINED 
AREAS OR SPACES WHERE IGNITION CAN OCCUR. THE AREA 
MUST BE WELL VENTILATED AND ALL SOURCES OF IGNITION MUST 
BE INACTIVATED OR REMOVED.
GAS METER SIZE — NATURAL GASES ONLY
Be sure the gas meter has suffi cient capacity to supply the full rated gas 
input of the water heater as well as the requirements of all other gas fi red 
equipment supplied by the meter.  If gas meter is too small, ask the gas 
company to install a larger meter having adequate capacity.
GAS PRESSURE REGULATOR
The gas pressure regulator is built into the gas valve and is equipped to 
operate on the gas specifi ed on model and rating plate. The regulator is 
factory adjusted to deliver gas to burner at correct water column pressure 
allowing for a nominal pressure drop through the controls.
The minimum gas supply pressure for input adjustment must not be less 
than 6 w.c. (1.49 kPa) for natural gas.
Do not subject the combination gas valve to inlet gas pressures of more 
than 14.0 w.c. (3.48 kPa) - natural gas.  A service regulator is necessary 
if higher gas pressures are encountered.
Gas pressure specifi ed in Table 5, refer to fl ow pressure taken at pressure 
tap of automatic gas valve while heater is operating.
TABLE 6. GAS PRESSURE
Type of
GasInput Manifold Pressure
Natural75,100 Btu/hr
22 KW/hr4.0 in. W.C.
1.12 kPa
OPERATION
It is recommended that a qualifi ed person perform the initial fi ring of the 
heater. At this time the user should not hesitate to ask the individual any 
questions which he may have in regard to the operation and maintenance 
of the unit.
TO OPERATE THE HEATER
1.  Close the heater drain valve (Figure 1) by turning handle clockwise .
2.  Open a nearby hot water faucet to permit the air in the system to 
escape.
3.  Fully open the cold water inlet pipe valve (Figure 1) allowing the heater 
and piping to be fi lled.
4.  Close the hot water faucet as water starts to fl ow.
5.  The heater is ready to be operated.
  WARNINGDO NOT ATTEMPT TO OPERATE WATER HEATER WITH COLD 
WATER INLET VALVE CLOSED.
NEVER OPERATE THE HEATER WITHOUT FIRST BEING CERTAIN IT IS 
FILLED WITH WATER AND A TEMPERATURE AND PRESSURE RELIEF 
VALVE IS INSTALLED IN THE RELIEF VALVE OPENING OF THE HEATER. 
TABLE 5 MAXIMUM CAPACITY OF PIPE IN 
CUBIC FEET PER HOUR
BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR GAS 
LEAKAGE. Use soap and water solution or other material acceptable for 
the purpose in locating the leaks. DO NOT USE MATCHES, CANDLES, 
FLAME OR OTHER SOURCES OF IGNITION FOR THIS PURPOSE.
FIGURE 5. GAS PIPING AND SEDIMENT TRAP INSTALLATION
 
DISCONNECT THE HEATER AND ITS MANUAL GAS SHUTOFF VALVE  
FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY SUPPLY 
PRESSURE TESTING EXCEEDING 1/2 PSIG (3.45 kPa). GAS SUPPLY 
LINE MUST BE CAPPED WHEN DISCONNECTED FROM THE HEATER  
FOR TEST PRESSURES OF 1/2 PSIG (3.45 kPa) OR LESS. THE WATER 
HEATER NEED NOT BE DISCONNECTED, BUT MUST BE ISOLATED  
FROM THE SUPPLY PRESSURE TEST BY CLOSING THE MANUAL GAS  
SHUTOFF VALVE.
LENGTH
IN
FEETNORMAL IRON PIPE SIZES (INCHES)
INPUT IN THOUSANDS BTU/HR
1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4
10175 360 680 1400 2100 3960 6300 11000 230000
20120 250 485 950 1460 2750 4360 7700 15800
3097 200 375 770 1180 2200 3520 6250 12800
4082 170 320 660 990 1900 3000 5300 10900
5073 151 285 580 900 1680 2650 4750 9700
6066 138 260 530 810 1520 2400 4300 8800
7061 125 240 490 750 1400 2250 3900 8100
8057 118 220 460 690 1300 2050 3700 7500
9053 110 205 430 650 1220 1950 3450 7200
10050 103 195 400 620 1150 1850 3250 6700
12544 93 175 360 550 1020 1650 2950 6000
15040 84 160 325 500 950 1500 2650 5500
17537 77 145 300 460 850 1370 2450 5000
20035 72 135 280 430 800 1280 2280 4600
LENGTH 
IN 
METERSNORMAL IRON PIPE SIZES (INCHES)
INPUT IN KW
1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4
3.051 105 199 410 615 1160 1845 3221 6735
6.135 73 142 278 428 805 1277 2255 4626
9.128 59 110 225 346 644 1031 1830 3748
12.224 50 94 193 290 556 878 1552 3192
15.221 44 83 170 264 492 776 1391 2840
18.319 40 76 155 237 445 703 1259 2577
21.318 37 70 143 220 410 659 1142 2372
24.417 35 64 165 202 381 600 1083 2196
27.416 32 60 126 190 357 571 1010 2108
30.515 30 57 117 182 337 542 952 1962
38.113 27 51 105 161 299 483 864 1757
45.712 25 47 95 146 278 439 776 1610
53.311 23 42 88 135 249 401 717 1464
61.010 21 40 82 126 234 375 688 1347