Installing the new water heater (cont’d), Temperature-pressure relief valve, Relief valve opening – State PR6 40 NHDST2 User Manual
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Installing the New Water Heater (cont’d)
Temperature-Pressure Relief Valve
DISCHARGE PIPE
(Do not cap or plug.
Must terminate
beneath manufactured
home, unless drain
pan is installed.)
TEMPERATURE-
PRESSURE
RELIEF VALVE
HOT
WATER
OUTLET
RELIEF VALVE OPENING
“THIS WATER HEATER IS PROVIDED WITH A COMBINATION TEMPERA-
TURE-PRESSURE RELIEF VALVE. FOR SAFE OPERATION OF THE WATER
HEATER, THE RELIEF VALVE(S) MUST NOT BE REMOVED FROM ITS DES-
IGNATED POINT OF INSTALLATION OR PLUGGED.
YOUR LOCAL JURISDICTIONAL AUTHORITY, WHILE MANDATING THE USE
OF A TEMPERATURE-PRESSURE RELIEF VALVE COMPLYING WITH ANSI
Z21.22 AND ASME, MAY REQUIRE A VALVE MODEL DIFFERENT FROM
THE ONE FURNISHED WITH THE WATER HEATER.
COMPLIANCE WITH SUCH LOCAL REQUIREMENTS MUST BE SATISFIED
BY THE INSTALLER OR END USER OF THE WATER HEATER WITH A
LOCALLY PRESCRIBED TEMPERATURE-PRESSURE RELIEF VALVE
INSTALLED IN THE DESIGNATED OPENING IN THE WATER HEATER.
SEE MANUAL HEADING—“TEMPERATURE-PRESSURE RELIEF VALVES”
FOR INSTALLATION AND MAINTENANCE OF RELIEF VALVE, DISCHARGE
LINE AND OTHER SAFETY PRECAUTIONS.
GAS SUPPLY
SHUTOFF
VALVE
TEE
DRIP LEG
(SEDIMENT TRAP)
PIPE CAP
MOUNTING BRACKETS
DRAIN VALVE
MOUNTING
BRACKET
COLD
WATER
INLET
VENT PIPE TO UL
LISTED ROOF JACK
WARNING
The temperature-pressure relief valve must be manually
operated at least once 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, and replace the temperature-pressure relief
valve with a new one.
WARNING
At the time of manufacture this water heater was provided
with a combination temperature-pressure relief valve certi-
fied by a nationally recognized testing laboratory that
maintains periodic inspection of production of listed
equipment or materials, as meeting the requirements for
Relief Valves and Automatic Gas Shutoff Devices for Hot
Water Supply Systems, and the latest edition of ANSI
Z21.22 and the code requirements of ASME. If replaced,
the valve must meet the requirements of local codes, but
not less than a combination temperature and pressure
relief valve certified as meeting the requirements for Relief
Valves and Automatic Gas Shutoff Devices for Hot Water
Supply Systems, ANSI Z21.22 by a nationally recognized
testing laboratory that maintains periodic inspection of
production of listed equipment or materials.
The valve must be marked with a maximum set pressure
not to exceed the marked hydrostatic working pressure of
the water heater (150 lbs./sq. in.) and a discharge capacity
not less than the water heater input rate as shown on the
model rating plate. (Electric heaters - watts divided by
1000 x 3415) equal BTU/Hr. rate.
Your local jurisdictional authority, while mandating the use
of a temperature-pressure relief valve complying with ANSI
Z21.22 and ASME, may require a valve model different
from the one furnished with the water heater.
Compliance with such local requirements must be satisfied
by the installer or end user of the water heater with a
locally prescribed temperature-pressure relief valve
installed in the designated opening in the water heater in
place of the factory furnished valve.
For safe operation of the water heater, the relief valve must
not be removed from it’s designated opening or plugged.
The temperature-pressure relief valve must be installed
directly into the fitting of the water heater designated for
the relief valve. Position the valve downward and provide
tubing so that any discharge will exit only within 6 inches
above, or at any distance below the structural floor. Be cer-
tain 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, 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
relief valve and the tank. Do not connect tubing directly to
discharge drain unless a 6
″″ air gap is provided. To prevent
bodily injury, hazard to life, or property damage, the relief
valve must be allowed to discharge water in quantities
should circumstances demand. If the discharge pipe is not
connected to a drain or other suitable means, the water
flow may cause property damage.
The discharge pipe:
—Must not be smaller in size than the outlet pipe size
of the valve, or have any reducing couplings or other
restriction.
—Must not be plugged or blocked.
—Must be of material listed for hot water distribution.
—Must be installed so as to allow complete drainage of
both the temperature-pressure relief valve, and the dis-
charge pipe.
—Must terminate at an adequate drain.
—Must not have any valve between the relief valve and tank.