Temperature-Pressure Relief Valve Test; Draining And Flushing - A.O. Smith GPVX 75L Series Installation And Operating Manual

Figure 41

TEMPERATURE-PRESSURE RELIEF VALVE TEST

DANGER
HOT
HOT
BURN
It is recommended that the temperature-pressure relief
valve be checked to ensure it is in operating condition at
least once a year.
When checking the temperature-pressure relief valve
operation, make sure that (1) no one is in front of or around
the outlet of the T&P valve discharge line, and (2) that
water discharge will not cause any property damage, as
water may be extremely hot. Use care when operating
valve as the valve may be hot.
To check the relief valve, lift lever at the end of valve
several times (see Figure 42). The valve should seat
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 "Draining And Flushing" section. Replace
the T&P valve with a properly rated/sized new one, see
"Temperature-Pressure Relief Valve" for instructions on
replacement.
100271597
ANODE ROD *
* THE ANODE ROD IS COVERED
BY URETHANE FOAM LOCATED
UNDER THE CAP. CHIP AWAY
THE FOAM TO EXPOSE THE
TOP OF THE ANODE ROD
• Burn hazard.
• Hot water discharge.
• Keep clear of
temperature-pressure
relief valve discharge.
CAP
If the Temperature-Pressure Relief Valve on the water
heater weeps or discharges periodically, it 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
Water Systems" and "Thermal Expansion" sections of this
manual. The T&P 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.

DRAINING AND FLUSHING

Periodic draining and cleaning of sediment from the tank
maybe necessary. It is recommended that the tank be
drained and flushed every 6 months to remove sediment
which may build up during operation. The water heater
should be drained if being shut down during freezing
temperatures. See "Typical Installation" section in this
manual for location of the water heater components
described below.
Figure 42
WARNING
Explosion Hazard
•
Temperature-pressure relief
valve must comply with ANSI
Z21.22-CSA4.4 and ASME
code.
•
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
•
Do not plug, block, or cap the
discharge line.
•
Failure to follow this warning
can result in excessive tank
pressure, serious injury or
death.
39