Installing the New Water Heater (cont’d)
Temperature-Pressure Relief Valve
10
DISCHARGE PIPE
(Do not cap or plug.
Must terminate
beneath
manufactured home.)
TEMPERATURE-
PRESSURE
RELIEF VALVE
COLD
HOT
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 main-
tains 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 current 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. p.s.i.) 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
3412) 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 local-
ly 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 discharge
pipe.
—Must terminate at an adequate drain.
—Must not have any valve between the relief valve and tank.
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.
RELIEF VALVE OPENING
“THIS WATER HEATER IS PROVIDED WITH A COMBINATION TEMPER-
ATURE-PRESSURE RELIEF VALVE. FOR SAFE OPERATION OF THE
WATER HEATER, THE RELIEF VALVE(S) MUST NOT BE REMOVED
FROM ITS DESIGNATED 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 DIF-
FERENT FROM THE ONE FURNISHED WITH THE WATER HEATER.
COMPLIANCE WITH SUCH LOCAL REQUIREMENTS MUST BE SATIS-
FIED 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.
