Bradford White THROUGH-THE-WALL GAS WATER HEATER Install And Operation Instructions page 27

WARNING
For protection against excessive temperatures and pressure, install temperature
and pressure protective equipment required by local codes, but not less than a
combination temperature and pressure relief valve certified by a nationally
recognized testing laboratory that maintains periodic inspection of production of
listed equipment or materials as meeting the requirements of the Standard for
Relief Valves and Automatic Gas Shutoff Devices for Hot Water Supply
Systems, ANS Z21.22 or the Standard CAN1-4.4. Temperature and Pressure
and the Standard CAN1-4.4, Temperature, Pressure, Temperature and Pressure
Relief Valves and Vacuum Relief Valves. The combination temperature and
pressure relief valve must be marked with a maximum set pressure not to
exceed the maximum working pressure of the water heater. The combination
temperature and pressure relief valve must also have an hourly rated temperature
steam BTU discharge capacity not less than the hourly rating of the water
heater.
Install the combination temperature and pressure relief valve into the opening
provided and marked for this purpose on the water heater.
Note: Some models may already be equipped or supplied with a combination
temperature and pressure relief valve. Verify that the combination temperature
and pressure relief valve complies with local codes. If the combination
temperature and pressure relief valve does not comply with local codes, replace
it with one that does. Follow the installation instructions above on this page.
Install a discharge line so that water discharged from the combination
temperature and pressure relief valve will exit within six (6) inches (15.2 cm)
above, or any distance below the structural floor and cannot contact any live
electrical part. The discharge line is to be installed to allow for complete drainage
of both the combination temperature and pressure relief valve and the discharge
line. The discharge opening must not be subjected to blockage or freezing. DO
NOT thread, plug or cap the discharge line. It is recommended that a minimum
clearance of four (4) inches (10.2 cm) be provided on the side of the water heater
for servicing and maintenance of the combination temperature and pressure relief
valve.
Do not place a valve between the combination temperature and pressure relief
valve and the tank.
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