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TEMPERATURE-PRESSURE RELIEF VALVE
This water heater is provided with a properly rated/sized and
certified combination Temperature-Pressure Relief Valve (T&P
valve) by the manufacturer. The valve is certified 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,
•
, and the code requirements of
ANSI Z21.22
CSA 4.4
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 certified 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 label.
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.
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 fitting of the water heater designed for the relief
valve. Install discharge piping so that any discharge will exit the
six inches (15.2 cm) above an adequate floor drain,
pipe within
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
air gap is provided. To prevent bodily injury, hazard to life, or
property damage, the relief valve must be allowed to discharge
water in adequate quantities if circumstances demand. If the
discharge pipe is not connected to a drain or other suitable means,
the water flow may cause property damage.
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.
ASME
six-inch (15.2 cm)
•
Temperature-Pressure Relief Valve discharge
pipe must terminate at adequate drain.
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 floor 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
.
relief valve and the drain.
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
Thermal Expansion
14).
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.
15
CAUTION
Water Damage Hazard
Burn hazard.
Hot water discharge.
Keep clear of Temperature-
Pressure Relief Valve
discharge outlet.
and
Closed Water Systems
(page
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