17
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 dis-
charge line.
• Must terminate a maximum of six inches above a floo r
drain or external to the building.
• Must be capable of withstanding 250°F (121°C) without
distortion.
• Must be installed to allow complete drainage of both
the valve and discharge line.
T&P Relief Valve and Pipe Insulation (Some Models)
1. Locate the T&P Relief Valve on the water heater.
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 15B. 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 tape.
IMPORTANT: The insulation or tape should not block
or cover the T&P Relief Valve drain opening. Also the
insulation or tape should not block or hinder access to the
T&P Relief Valve manual relief lever.
4. Next locate the hot water (outlet) & cold water (inlet) pipes
to the water heater.
5. Select one of the sections of pipe insulation and locate
the slit that runs the length of the insulation.
6. Spread the slit open at the base of the insulation and slip
it over the cold water (inlet) pipe. Apply gentle pressure
along the length of the insulation to ensure it is fully
seated around the cold water pipe. Also ensure that the
base of insulation is flush with the water heater. Once
seated, secure the insulation with a section of tape.
7. Repeat steps 5 through 6 for the hot water (outlet) pipe.
T&P RELIEF VALVE
DRAIN LINE
T&P RELIEF VALVE
MANUAL RELIEF LEVER
T&P RELIEF VALVE INSULATION
FIGURE 15B.
Combination Space Heating/Potable
Water System
Some water heater models are equipped with inlet/outlet
connections for use with space heating applications. If this
water heater is to be used to supply both space heating
and domestic potable (drinking) water, the instructions
listed below must be followed.
Temperature and Pressure Relief Valve Explosion Harzard
• 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.
TEMPERATURE AND PRESSURE (T&P)
RELIEF VALVE (OPTIONAL TOP T&P
RELIEF VALVE NOT SHOWN)
DRAIN LINE
3/4” ID
MINIMUM
DRAIN
1” MINIMUM
6” MAXIMUM
AIR GAP
METAL
DRAIN PAN
DISCHARGE PIPE
(DO NOT CAP OR PLUG)
FIGURE 15A.
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 15A). 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 par t.
• 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