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For protection against excessive pressures and temperatures,
a temperature and pressure relief valve must be installed in the
opening marked “T & P RELIEF VALVE” (see Figure 25). This
valve must be design certified by a nationally recognized testing
laboratory that maintains periodic inspection of the production
of listed equipment or materials as meeting the requirements
for Relief Valves for Hot Water Supply Systems, ANSI Z21.22.
The function of the temperature and pressure relief valve is to
discharge water in large quantities in the event of excessive
temperature or pressure developing in the water heater. The
valve’s relief pressure must not exceed the working pressure of
the water heater as stated on the rating plate.
IMPORTANT: Only a new temperature and pressure relief valve
should be used with your water heater. Do not use an old or
existing valve as it may be damaged or not adequate for the
working pressure of the new water heater. Do not place any valve
between the relief valve and the tank.
The Temperature & Pressure Relief Valve:
• Must not be in contact with any electrical part.
• Must be connected to an adequate discharge line.
• Must not be rated higher than the working pressure shown
on the rating plate of the water heater.
The Discharge Line:
• Must not be smaller than the pipe size of the relief valve or
have any reducing coupling installed in the discharge line.
• Must not be capped, blocked, plugged or contain any valve
between the relief valve and the end of the discharge line.
• Must terminate a maximum of six inches above a floor drain
or external to the building. In cold climates, it is recommend-
ed that the discharge pipe be terminated at an adequate
drain inside the building.
• Must be capable of withstanding 250°F (121°C) without dis-
tortion.
• Must be installed to allow complete drainage of both the
valve and discharge line.
T&P Relief Valve and Pipe Insulation
1. Locate the temperature and relief valve on the water heater
(also known as a T&P Relief Valve, Figure 26).
2. Locate the slit running the length of the insulation.
3 Spread this slit open and slip it up under the T&P Relief Valve.
See Figure 26. Apply gentle pressure to the insulation to ensure
it is fully seated on the T&P Relief Valve. Once sealed secure
the insulation with a section of duct tape, electrical tape, or
equivalent.
IMPORTANT: The insulation or tape must not block the
discharge opening or hinder access to the manual relief
lever. Ensure a discharge pipe is installed into the T&P valve
discharge opening per the instructions manual.
4. Locate the hot water (outlet) & cold water (inlet) pipes to the
water heater.
5. Locate the slit running the length of a section of pipe insulation.
6. Spread the slit open and slip the insulation over the cold
water (inlet) pipe. Apply gentle pressure along the length of
the insulation to ensure it is fully seated around the pipe. Also
ensure that the base of insulation is flush with the water heater.
Once seated, secure the insulation with duct tape, electrical
tape, or equivalent.
7. Repeat steps 5 through 6 for the hot water (outlet) pipe.
8. Add additional sections of pipe insulation as needed.
T&P Relief Valve Insulation
Manual Relief Lever
T&P Relief Valve
T&P Relief Valve
Drain Line
FIGURE 26.