Temperature & Pressure Relief Valve; T&P Relief Valve And Pipe Installation; Combination Space Heating/Potable Water System - Lochinvar RESIDENTIAL GAS WATER HEATERS Use And Care Manual With Installation Instructions

Temperature and Pressure Relief Valve
1" MINIMUM
DO NOT CAP OR PLUG
METAL
DRAIN PAN
DRAIN
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 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 dis-
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 RELIEF (T&P)
VALVE (OPTIONAL TOP T&P RELIEF
VALVE NOT SHOWN)
DISCHARGE PIPE
DRAIN LINE 3/4"
ID MINIMUM
6" MAXIMUM
AIR GAP
FIGURE 15A.
charge line.
• Must terminate a maximum of six inches above a floor
drain or external to the building. In cold climates, it is
recommended that the discharge pipe be terminated at
an adequate drain inside 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 temperature and pressure relief valve on
the water heater (also known as a T&P relief valve).
See Figure 15B.
2. Locate the slit running the length of the T&P relief
valve insulation.
3. Spread the slit open and fit the insulation over the T&P
relief valve. See Figure 15B. Apply gentle pressure
to the insulation to ensure that it is fully seated on the
T&P Relief Valve. Once seated, secure the insulation
with duct tape, electrical tape, or equivalent.
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 manual relief lever (Figure 15B). Ensure
that a discharge pipe is installed into the T&P valve
discharge opening per the instructions in this 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 that it is fully seated around
the pipe. Also, ensure that the base of the insulation is
flush with the water heater. Once seated, secure the
insulation with duct tape, electrical tape, or equivalent.
7. Repeat steps 5 and 6 for the hot water (outlet) pipe.
8. Add additional sections of pipe insulation as needed.
MANUAL RELIEF
LEVER
T&P RELIEF
VALVE
T&P RELIEF VALVE
DRAIN LINE
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.
• Be sure to follow the manual(s) shipped with the air
handler system.
17
T&P RELIEF VALVE INSULATION
FIGURE 15B.