John Wood Polaris Commercial High-Efficiency - Manual (Page 14)

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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, 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 Pan
6” (15.2cm)
Air Gap Max.
Adequate Drain