22

Water Damage Hazard

Temperature-Pressure Relief Valve discharge
pipe must terminate at adequate drain.

•

CAUTION
T&P VALVE DISCHARGE PIPE REQUIREMENTS:
• Shall not be smaller in size than the outlet pipe size of the valve,
or have any reducing couplings or other restrictions.
• Shall not be plugged or blocked.
• Shall not be exposed to freezing temperatures.
• Shall be of material listed for hot water distribution.
• Shall be installed so as to allow complete drainage of both the
Temperature-Pressure Relief Valve and the discharge pipe.
• Must terminate a maximum of six inches (15.2 cm) above a
oor drain or external to the building. In cold climates, it is
recommended that the discharge pipe be terminated at an
adequate drain inside the building.
• Shall not have any valve or other obstruction between the
temperature-pressure relief valve and the drain.
Burn hazard.Hot water discharge.Keep clear of Temperature-Pressure Relief Valvedischarge outlet.
The Temperature-Pressure Relief Valve must be manually
operated at least twice a year. Caution should be taken to
ensure that (1) no one is in front of or around the outlet of the
Temperature-Pressure Relief Valve discharge line, and (2)
the water manually discharged will not cause any bodily injury
or property damage because the water may be extremely hot.
If after manually operating the valve, it fails to completely reset
and continues to release water, immediately close the cold water
inlet to the water heater, follow the draining instructions in this
manual, and replace the Temperature-Pressure Relief Valve with
a properly rated/sized new one.
NOTE: The purpose of a Temperature-Pressure Relief Valve is to
prevent excessive temperatures and pressures in the storage tank.
The T&P valve is not intended for the constant relief of thermal
expansion. A properly sized thermal expansion tank must be
installed on all closed systems to control thermal expansion, see
Closed Water Systems and Thermal Expansion on Page 21.
If you do not understand these instructions or have any questions
regarding the Temperature-Pressure Relief Valve call the toll
free number listed on the back cover of this manual for technical
assistance.
TEMPERATURE-PRESSURE RELIEF VALVE
This water heater is provided with a properly rated/sized and certied
combination Temperature-Pressure Relief Valve (T&P relief valve) by
the manufacturer. The valve is certied by a nationally recognized
testing laboratory that maintains periodic inspection of production of
listed equipment of materials as meeting the requirements for Relief
Valves for Hot Water Supply Systems, ANSI Z21.22 • CSA 4.4, and
the code requirements of ASME.
If replaced, the new T&P valve must meet the requirements
of local codes, but not less than a combination Temperature-
Pressure Relief Valve rated/sized and certied as indicated in
the above paragraph. The new valve must be marked with a
maximum set pressure not to exceed the marked hydrostatic
working pressure of the water heater (150 psi = 1,035 kPa) and
a discharge capacity not less than the water heater Btu/hr or kW
input rate as shown on the water heater’s model rating plate.
NOTE: In addition to the factory installed Temperature-Pressure
Relief Valve on the water heater, each remote storage tank
that may be installed and piped to a water heating appliance
must also have its own properly sized, rated and approved
Temperature-Pressure Relief Valve installed. Call the toll free
technical support phone number listed on the back cover of
this manual for technical assistance in sizing a Temperature-
Pressure Relief Valve for remote storage tanks.

Explosion Hazard

Temperature-Pressure Relief Valve
must comply with ANSI Z21.22-
CSA 4.4 and ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure.
Can cause serious injury or death.
For safe operation of the water heater, the Temperature-
Pressure Relief Valve must not be removed from its designated
opening nor plugged. The Temperature-Pressure Relief Valve
must be installed directly into the tting of the water heater
designed for the relief valve. Install discharge piping so that any
discharge will exit the pipe within 6 inches (15.2 cm) above an
adequate oor drain, or external to the building. In cold climates
it is recommended that it be terminated at an adequate drain
inside the building. Be certain that no contact is made with any
live electrical part. The discharge opening must not be blocked
or reduced in size under any circumstances. Excessive length,
over 30 feet (9.14 m), or use of more than four elbows can cause
restriction and reduce the discharge capacity of the valve.
No valve or other obstruction is to be placed between the
Temperature-Pressure Relief Valve and the tank. Do not connect
discharge piping directly to the drain unless a 6” (15.2 cm) air gap
is provided. To prevent bodily injury, hazard to life, or property
damage, the temperature-pressure relief valve must be allowed
to discharge water in adequate quantities should circumstances
demand. If the discharge pipe is not connected to a drain or other
suitable means, the water ow may cause property damage.