American Water Heater Polaris High Efficiency Commercial Gas Water Heater PCG3 User Manual

							11
INLET/OUTLET VENT TERMINATIONS
Standard Horizontal Termination
When 3 inch pipe is used between the water heater and the 
outside wall, reduce it to 2 inch pipe before penetrating the 
wall. A maximum of 18 inches (45.7 cm) of 2 inch pipe may 
be used between the 3 inch transition and the inside of the 
wall (see figure 7).
The standard horizontal air inlet termination is a 2 inch 
pipe which terminates at the exterior wall and utilizes a 
coupling to prevent the pipe from being pushed back into the 
structure. The standard horizontal exhaust outlet termination 
is a 2 inch pipe which terminates 12 inches (30.5 cm) from 
the outside wall. The air inlet must be located with respect to 
the exhaust outlet as shown in figure 7 (bottom).
Install a drain tee assembly and trap in the inlet vent as close 
to the water heater as possible. This is to drain any water 
that may be in the combustion air pipe and prevent it from 
entering the blower.  Connect the trap drain line to a suitable 
drain or downstream of the condensate trap of the water 
heater.
Note: See “Venting Additional Polaris
® Units” on Page 12 
for correct terminations if installing more than one Polaris® 
gas water heater.  
Alternative Horizontal Termination
The combustion air and exhaust terminations may be 
raised up to 24 inches (61 cm) above the wall penetrations 
if required for anticipated snow levels (see figure 8).  The 
two elbows shown in figure 8 are considered part of the 
termination and should not be included when determining 
the maximum allowable vent pipe length.
Note: See “Venting Additional Polaris
® Units” on Page 12 
for correct terminations if installing more than one Polaris® 
gas water heater.  
(30.5 cm)
24”
(61 cm)
Max.
(76.2 cm)
Figure 7: Standard Horizontal Termination
3” (7.6cm) Max.
4” (10 cm) 
Max.
4” (10 cm) 
Max.12” (30.5 cm) 
2” 
Coupling  
12” (30.5cm) Min. Above
Grade or Anticipated
Snow Level.  See
Note 4.
Notes:
1.  Support Horizontal Pipe Every 
Four Feet (1.2 m).  Support Vertical 
Pipe Every Six Feet (1.8 m).
2.  When Using 3 Inch Pipe,  Reduce To 2 Inches Before 
Penetrating The Outside Wall.
3.  18 Inch (45.7 cm) Maximum When Using 3 Inch Pipe.
4.  Increase The 12 Inch (30.5 cm) Minimum Above 
Grade To Keep Terminal Openings Above Anticipated 
Snow Levels.
5.   Slope All Piping Down Toward the Water Heater as 
Follows: 
 
						

							12
VERTICAL TERMINATIONS
When 3 inch pipe is used between the water heater and the 
roof, reduce it to 2 inch pipe before penetrating the roof. 
A maximum of 18 inches (45.7 cm) of 2 inch pipe may be 
used between the 3 inch transition and the inside of the 
roof.
The vertical inlet air termination requires a return bend 
or two short or long sweep radius 90 elbows to keep the 
inlet downward and prevent entry of rain. These elbows 
are considered part of the termination and should not be 
included when calculating the maximum allowable vent 
pipe length. Refer to figure 9 for the proper location of the 
air inlet with respect to the exhaust outlet termination. The 
vertical exhaust outlet termination is a 2 inch (30.5 cm) pipe which terminates at least 12 inches (30.5 cm) above the 
inlet air termination.
The air inlet and exhaust outlet terminations must be at 
least 12 inches (30.5 cm) above the roof line or anticipated 
snow levels.  See figure 9 below.
Note: See “Venting Additional Polaris
® Units” below if 
installing more than one Polaris® gas water heater.  
 
Venting Additional Polaris® Units
When using two (2) Polaris® units, install vent terminations 
using either Method A or Method B below:When using three or more Polaris
® units, install vent 
terminations per Method C or Method D:
Figure 9: Vertical Termination
Notes:
1.  Support Horizontal Pipe Every 
Four Feet (1.2 m).  Support Vertical 
Pipe Every Six Feet (1.8 m).
2.  When Using 3 Inch Pipe,  Reduce To 
2 Inches Before Penetrating The 
Roof.
3.  18 Inch (45.7 cm) Maximum When 
Using 2 Inch Pipe.
4.  Increase The 12 Inch (30.5 cm) 
Minimum Above Grade To Keep 
Terminal  Openings Above Anticipated 
Snow Levels.4” (10 cm)  Max.
12” (30.5cm) Min. 
Above Roof or 
Anticipated Snow 
Level.  See Note 4.12” (30.5 cm) Min. 
12” (30.5 cm) 
Min. 
4” (10 cm)  
Max.
12” 
(30.5 cm) 
Min. 
*
*
3” (7.6cm) Max.
4” (10cm) 
Max.
3” 
(7.6 cm) 
Max.
4” 
(10cm) 
Max.36” (91.4 cm) 
Minimum3” (7.6 cm) Max.
4” 
(10cm) 
Max.
3” 
(7.6 cm) 
Max.
4” 
(10cm) 
Max. 4” 
(10cm) 
Max.36” (91.4 cm) 
Minimum
4” 
(10cm) 
Max.4” 
(10cm) 
Max.4” 
(10cm) 
Max.
36” (91.4 cm) 
Minimum36” (91.4 cm) 
Minimum
Figure 9A, 9BFigure 9C, 9D 
						

							13
CONCENTRIC VENT TERMINATIONS
For new installations, install 2” Concentric vent kit model 
KGAVT0501CVT, part number 6910542.  See Manufacturer’s 
instructions for complete installation or call customer service at 
1-800-456-9805 for assistance or go to www.americanwaterheater.com.   
For planning purposes, see figures 10-13 below for vent terminal 
specifications.
Note:  For replacement installations, previously installed 
American Water Heater Company supplied concentric vent kits 
are acceptable for use on 100,000-130,000 BTU/Hr models only. 
Make sure that the existing vent complies with current codes.
(14.6cm)
(15.7cm)
(8.9cm Dia.)
(42.2cm)
(84.77cm)(4.8cm)(3.8cm)
Figure 10: 2 Inch Concentric Vent
(2.54cm)
Figure 11: Through the Wall Termination
12” (30.5cm) Minimum 
clearance above 
anticipated snow level.  
24” (61cm) Max.
Figure 12: Through the Roof Termination
Notes:
1.  Support Horizontal Pipe Every 
Four Feet (1.2 m).  Support 
Vertical Pipe Every Six ft. (1.8 m).
4.  Increase The 12 Inch (30.5 cm) 
Minimum Above Grade To Keep 
Inlet Opening Above Anticipated 
Snow Levels.
5.   Slope All Piping Down Toward 
the Water Heater as follows: 
 
						

							14
Figure 14: Input GraphGas Input Rate
The gas input rate of this water heater is affected by 
several environmental factors such as:
• The heating value of the gas
• The air and gas densities (which vary widely due to baro-
metric pressure and temperature changes)
• Venting installations (pipe diameter, length and fittings)
• Altitude
When measuring the input rate these factors should be 
incorporated into the calculations. Also measure the gas 
consumption over a sufficiently long time to obtain an 
accurate gas consumption rate (e.g. 3-5 minutes, not one 
revolution of the meter needle).
Long vents and each additional elbow, inherently reduce 
the gas input rate due to increased resistance to moving 
combustion air and flue gases. The approximate maximum/
minimum input for the 100k, 130k, and 150k models is 
shown in figure 15.
WATER PIPING SYSTEM
Piping Installation
Piping, fittings, and valves should be installed according to 
the installation drawing (figure 15). If the indoor installation 
area is subject to freezing temperatures, the water piping 
must be protected by insulation. 
The water supply pressure should not exceed 80 psi 
(551.5 kPa). If this occurs, a pressure reducing valve with a 
bypass should be installed in the cold water inlet line. This 
should be placed on the supply to the entire house in order 
to maintain equal hot and cold water pressures.
Important: Heat cannot be applied to the water fittings 
on the heater as they may contain nonmetallic parts. 
If solder connections are used, solder the pipe to the 
adapter before attaching the adapter to the hot and 
cold water fittings. 
Important:  Do not install this water heater with iron or 
galvanized piping.  Use brass caps on all unused inlet/
outlet connections. 
1.  Install the water piping and fittings as shown in figure 
15. Note: If state or local codes require, install a vacu-
um relief valve per the manufactures instructions in the 
cold water supply line. Connect the cold water supply 
(use 1” NPT) to the fitting marked “COLD INLET”.  
Do not turn the cold water nipple. The mark should         
remain along the top side of the nipple. Connect the 
hot water supply (use 1” NPT) to the fitting marked 
“HOT OUTLET”. 
2.  Always use a suitable grade of joint compound and be 
certain that all fittings are tightened properly.
3.  The installation of unions in both the hot and cold water 
supply lines is recommended for ease of removing the 
water heater for service or replacement.
4.  If installing the water heater in a closed water system, 
install an expansion tank in the cold water line as speci-
fied under “Closed System/Thermal Expansion” (Page 
15).
5.  Install a shut-off valve in the cold water inlet line.  It 
should be located close to the water heater and be 
easily accessible. Know the location of this valve and 
how to shut off the water to the heater.6. The Polaris
® gas water heater is shipped with a factory-
installed Temperature and Pressure Relief Valve.  
Install a discharge line in the opening in the T & P valve 
(see instructions on Page 17).
7.  After piping has been properly connected to the water  
heater, remove the aerator at the nearest hot water    
faucet.  Open the hot water faucet and allow the tank  
to completely fill with water. (To prevent damage to 
the unit, DO NOT connect power until the tank is 
COMPLETELY FILLED). To purge the lines of any  
excess air, keep the hot water faucet open for 3 min-
utes after a constant flow of water is obtained. Close 
the  faucet and check all connections for leaks.
Corrosion and Water Quality
Water quality will vary from location to location and may 
contain contaminates that may reduce the life or perfor-
mance of the water heater. To test for contaminates a 
water quality test kit is available, reference part number 
6903791.
Contaminates which can reduce the life or performance 
of the water heater if present in high quantities include 
those which contribute to hardness (dissolved minerals 
such as sodium, calcium and magnesium); plus chlorides 
and sulfates. Additionally, water that is too acidic or basic 
(measured as pH) can reduce the life of the water heater. 
Water treatment systems (such as water softeners for 
hardness) should be used and maintained properly if the 
contaminate levels exceed the following:
Warranty is void in applications which exceed the 
water quality requirements listed below.
Table 2:
Total Hardness:12 grains per gal. (205 mg/liter) max.
Chloride: 200 mg/liter max.
pH: 6.5-8.0
Alkalinity: 200 mg/liter max. 
						

							15
Figure 15: Typical One-Temperature System Piping Installation
Mixing Valve Installation
A mixing valve has been provided for use with the 
Polaris®  Gas water heater and must be installed, per the 
manufacturer’s instructions, in the domestic hot water line.  
See Figure 16 for a sample tempering valve installation.
General Information
Water piping, fittings, and valves must be properly installed 
for the correct and safe operation of this water heater. 
Please note the following:
•  The system should be installed only with piping that is 
suitable for potable (drinking) water such as copper, 
CPVC, PEX or polybutylene. PVC water piping may be 
used on the cold water   inlet supply but not within 18 
inches (45.7 cm) of the cold water connection on the 
water heater.  
•  Do not use PVC piping on the hot water outlet,      
space heating supply, or space heating return.
•  Do not use any pumps, valves, or fittings that are      
not compatible with potable water.
•  Do not use valves that may cause excessive      
restriction to water flow. Use full flow ball or gate      
valves only.
•  Do not use 50/50 tin-lead solder (or any lead based    
solder) in potable water lines. Use 95/5 solder or      
other equivalent material.
•  Do not tamper with the thermostat, gas valve,     
blower, electrical components, or temperature and   
pressure relief valve. Tampering with any of the      
components is dangerous and can result in death,   
severe injury, or property damage. Tampering voids  
all warranties. Only qualified technicians should     
service these components.
•  Do not use this water heater as a replacement for an 
existing boiler installation.
•  Do not use with piping that has been treated with      
chromates, boiler seal, or other chemicals.
•  Do not add any chemicals to the system piping      
which will contaminate the potable water supply.
Closed System/Thermal Expansion
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 correspond-
ing increase in water pressure due to thermal expansion.  
Thermal expansion can cause premature tank failure (leak-
age). This type of failure is not covered under the limited 
warranty. Thermal expansion can also cause intermittent 
temperature-pressure relief valve operation; water dis-
charged 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 regarding the installation of a 
thermal expansion tank.  The manufacturer of this water 
heater will void the warranty if there is a failure to 
install a properly sized expansion tank. 
Combination Space Heating/Potable 
Water System 
Some water heater models are equipped with inlet/
outlet connections for use in space heating applications.       
Note: this water heater, “Suitable for combination water 
(potable) heating and space heating and not suitable for 
space heating applications only.” If this water heater is to be 
used to supply both space heating and potable (drinking) 
water, the instructions listed below must be followed (see 
figure 17).
•  Be sure to follow the manual(s) shipped with the  air 
handler or other type heating system.
•  This water heater is not to be used as a replacement  
for an existing boiler installation.
Check local codes.
(set to 120° F 
[48.8° C] or lower)
Figure 16: Sample Mixing
Valve Installation
Mixing Valve
Mixing Valve
Metal Drain Pan6” (15.2cm) 
Air Gap Max.
Adequate Drain 
						

							16 •  Do not use with piping that has been treated with 
chromates, boiler seal or other chemicals and do not 
add any chemicals to the water heater piping.
•  If the space heating system requires water temperatures 
in excess of 120°F (48.9°C), a mixing valve (provided) 
must be installed per the manufacturer’s instructions 
in the potable hot water supply to limit the risk of scald 
injury.
•  Pumps, valves, piping and fittings must be compatible  
with potable water.
•  A properly installed flow control valve is required to pre-
vent thermosiphoning. Thermosiphoning is the result 
of a continuous flow of water through the air handler  
circuit during the off cycle. Weeping (blow off) of the  
temperature and pressure relief valve (T & P) or higher  
than normal water temperatures are the first signs of    
thermosiphoning.
•  The hot water line from the water heater should be ver-
tical past any mixing valve or supply line to the heating 
system to remove air bubbles from the system.
• Do not connect the water heater to any system or 
components previously used with non-potable water   
heating appliances when used to supply potable water.
Storage Tank Installation 
When installing the Polaris® with a storage tank, see figure 
18 for piping suggestions.
Solar Installation
If this water heater is used as a solar storage heater or as 
a backup for the solar system, the water supply tempera-
tures to the water heater tank may be in excess of 120°F 
(48.9°C). A mixing valve must be installed in the water sup-
ply line to limit the supply temperature to 120°F (48.9°C).
Note:  Solar water heating systems can often supply water 
with temperatures exceeding 180°F (82.2°C) and may 
result in water heater malfunction.
Figure 17: Air Handler Piping Installation
Mixing Valve
Metal Drain Pan
6” (15.2cm) 
Air Gap Max.
Adequate Drain
Massachusetts code does not allow this type of installation. 
						

							17
Temperature and Pressure 
Relief Valve
For protection against excessive pressures and tempera-
tures, a temperature and pressure relief valve must be 
installed in the opening marked “T & P RELIEF VALVE”.  
This valve must be design certified by a nationally recog-
nized testing laboratory that maintains periodic inspection 
of the production of listed equipment or materials as meet-
ing the requirements for Relief Valves and Automatic Shut-off Devices for Hot Water Supply Systems, ANSI Z21.22. 
The function of the temperature and pressure relief valve is 
to discharge water in large quantities in the event of exces-
sive temperature or pressure developing in the water heat-
er. The valve’s relief pressure must not exceed the working 
pressure of the water heater as stated on the data plate.
Important:  Only a new temperature and pressure relief 
valve should be used with this water heater. Do not use 
an old or existing valve as it may be damaged or not ade-
quate for the working pressure of the new water heater. Do 
not place any valve or piping between the relief valve and 
the tank.
The Temperature & Pressure Relief Valve:   
•  Must not be in contact with any electrical part.
•  Must be connected to an adequate discharge line.
•  Must not be rated higher than  the working pressure  
shown on the data plate of the water heater.
•  The BTUH rating of the T & P valve must be  greater 
than, or equal to, the input rating of the water heater
The Discharge Line:
•  Must not be smaller than the pipe size of the relief 
valve or have any reducing coupling installed in the 
discharge line.
•  Must not be capped, blocked, plugged or contain any 
valve between the relief valve and the end of the dis-
charge line.
•  Must terminate a maximum of 6 inches (15.2 cm) 
above a floor drain or external to the building.
•  Must be capable of withstanding 250°F (121°C) without 
distortion.
•  Must be installed to allow complete drainage of both 
the valve and discharge line.
Mixing
ValveTank 
Temperature
Control
(170°F [76.6°C] Max.)
(If Used)
Figure 18: Polaris® with Auxillary Storage Tank - One or Two 
Temperature System (With or Without Building Recirculation)Notes on Figure 18:
If tank temperature is set above 
120°F (48.9°C) and water is sup-
plied for domestic use (hand wash-
ing, showering, etc.) a mixing valve 
must be installed in the hot water 
line to domestic fixtures.
Installation must conform to local 
code requirements. If a check valve 
is installed in the cold water sup-
ply line, an expansion tank must be 
installed between the check valve 
and the water heater’s cold water 
inlet.  Set storage tank temperature 
five degrees lower than the water 
heater’s temperature setting.  Using 
the plug valve in the recirculating 
line, adjust the flow in the recirculat-
ing line to five gallons per minute.
Explosion Hazard
• Temperature-pressure relief valve must 
comply with ANSI Z21.22-CSA 4.4 and 
ASME code.
• A properly-sized temperature-pressure 
relief valve must be installed in the 
opening provided.
• Do not plug, block, or cap the discharge 
line.
• Failure to follow this warning can result in 
excessive tank pressure, serious injury 
or death. 
						

							18
GAS SUPPLY AND PIPING
Gas Requirements
Read the data plate to be sure the water heater is made 
for the type of gas being used.  This information will be 
found on the data plate located on the front of the water 
heater. If the information does not agree with the type of 
gas available, do not install or operate the water heater. 
Call your dealer.
Note:  An odorant may be added by the gas supplier to 
the gas used by this water heater. This odorant may fade 
over an extended period of time. Do not depend upon this 
odorant as an indication of leaking gas.
Gas Piping
The gas piping must be installed according to all local and 
state codes or in absence of local and state codes with the 
“National Fuel Gas Code”, ANSI Z223.1 (NFPA 54)-current 
edition. Canadian installations must be performed in 
accordance with CAN/CSA-B149.1-current edition.      
Note:  If using a flexible gas connector, make sure its rating 
tag matches or exceeds the input of the water heater.
Follow the instructions below and reference figure 19 for 
gas piping installation.
1.  Install a readily accessible manual shut-off valve in the 
gas supply line as recommended by the  local utility. 
Know the location of this valve and how to turn off the 
gas to this unit.
2.  Install a drip leg as shown. The drip leg must be no  
less than 3 inches (7.62 cm) long for the accumulation 
of dirt,   foreign material and water droplets.
3.  Install a ground joint union between the water heater  
and the manual shut-off valve.  This is to allow easy  
servicing.
4.  Turn the gas supply on and check for leaks. Use a 
chloride-free soap and water solution (bubbles forming 
indicate a leak) or other approved method.
3” (7.62 cm)
Minimum 
Figure 19: Gas Piping Installation
Gas Pressure
Important: The gas supply pressure must not exceed the 
maximum supply pressure as stated on the water heater’s 
data plate.  Minimum supply pressure should also be 
maintained per the data plate. 
Explosion Hazard
Use a new AGA or CSA approved gas 
supply line.
Install a shut-off valve.
Do not connect a natural gas water 
heater to a L.P. Gas Supply.
Do not connect an L.P. gas water heater 
to a Natural Gas Supply.
Failure to follow these instructions can 
result in death, explosion, or carbon 
monoxide poisoning. 
						

							19
Gas Pressure Testing
Important: This water heater and its gas connection must 
be leak tested before placing the appliance in operation.  
• If the code requires the gas lines to be tested at  a 
pressure of 14” W.C. (3.486 kPa) or greater, the water 
heater and its manual shut-off valve must be discon-
nected  from the gas supply piping system and the line  
capped.
• If the gas lines are to be tested at a pressure less   
than 14” W.C. (3.486 kPa), the water heater must be 
isolated from the gas supply piping system by closing 
its manual shut-off valve.
Nationally listed/recognized fuel gas and carbon 
monoxide(CO) detectors are recommended in 
all applications and should be installed using the 
manufacturer’s instructions and local codes, rules, or 
regulations.
Note: Air may be present in the gas lines and could prevent 
the burner from lighting on initial start-up. The gas lines 
should be purged of air by a qualified service technician 
after installation of the gas piping system.   
Explosion Hazard
Have a qualified person make sure that 
the L.P. gas operating pressure does not 
exceed 13” water column (3.237 kPa).
Examples of a qualified person include 
licensed heating personnel, authorized 
gas company personnel, and authorized 
service personnel.
Failure to do so can result in death, 
explosion, or fire. 
						

							20
Electrical Shock Hazard
Disconnect power before
servicing.
Replace all parts and panels
before operating.
Failure to do so can result in 
death or electrical shock.
ELECTRICAL CONNECTIONS
Figure 20: Electrical Connections
If you lack the necessary skills required to properly install 
the electrical wiring to this water heater, do not proceed but 
have a qualified electrician perform the installation.
When making the electrical connections, always make 
sure:
• The voltage and frequency correspond to that specified 
on the water heater data plate on the front of the water 
heater.
• The electrical supply has the proper overload fuse  
or breaker protection.  The heater draws less than 7 
amps.
• Wire sizes and connections comply with all applicable 
codes.
• Wiring enclosed in approved conduit (if required by lo-
cal codes).
•  The water heater and electrical supply are properly    
grounded.
•  This water heater must be “hard-wired” - do not use an 
extension cord to supply electrical power to this water 
heater.
Note:
The wiring diagram can be found on Page 21.  Always 
reference the wiring diagram(s) for the correct electrical 
connections. 
When installing the electrical wiring to the water heater:
1.  Shut off the power at the electrical service box.
2.  Loosen the screws securing the access panel to  the 
electrical compartment. (The electrical wiring diagram. 
models can be found on the inside of the access panel 
at the base of the water heater.) Set the access panel 
aside. 
3.  Connect the electrical supply to the water heater in 
accordance with local utility requirements and codes.  
Use only a dedicated electrical circuit containing a 
properly sized fuse or circuit breaker. Maximum over-
load protection should not exceed 15 amperes. 4.  Connect this circuit (directly from the electrical  service 
box) to an electrical disconnect switch. 
5.  Ground the water heater by connecting the electrical  
service ground wire to the green ground wire (provided).
Note:  The power supply to this water heater must be 
properly polarized, [120 volts from the hot lead (black) to 
ground and 0 volts from the neutral lead (white) to ground] 
otherwise, the unit will not operate.
6.  After making all electrical connections, completely fill    
the tank with water and check all connections for leaks.  
Open the nearest hot water faucet and let it run for 3    
minutes to purge the water lines of air and sediment     
and to ensure complete filling of the tank.  The electri-
cal power may then be turned on.  See figure 20 for 
completed installation.