Lochinvar LTN07575 Instruction Manual page 29

be extremely hot. Use care when operating valve as the
valve may be hot.
To check the relief valve, lift the lever at the end of the
valve several times, see . The valve should seat
Figure 22
properly and operate freely.
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 and drain the
water heater, see (page 30).
Draining and Flushing
Replace the temperature-pressure relief valve with a
properly rated/sized new one, see
Temperature-Pressure
(page 14) for information on replacement.
Relief Valve
TEMPERATURE-PRESSURE
RELIEF VALVE
DISCHARGE PIPE
FIGURE 22. CHECKING THE RELIEF VALVE
If the temperature-pressure relief valve on the water
heater weeps or discharges periodically, this may be due
to thermal expansion.
NOTE: Excessive water pressure is the most common
cause of temperature-pressure relief valve leakage.
Excessive water system pressure is most often caused
by thermal expansion in a "closed system." See
Closed
(page 13) and
Water Systems Thermal Expansion
(page 13). The temperature-pressure relief valve is not
intended for the constant relief of thermal expansion.
Temperature-pressure relief valve leakage due to
pressure build up in a closed system that does not have
a thermal expansion tank installed is not covered under
the limited warranty. Thermal expansion tanks must be
installed on all closed water systems.
DO NOT PLUG THE TEMPERATURE-PRESSURE
RELIEF VALVE OPENING. THIS CAN CAUSE
PROPERTY DAMAGE, SERIOUS INJURY OR DEATH.
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