Temperature-Pressure Relief Valve Test - A.O. Smith 100 Series Instruction Manual

5. Attach element wires to connection points from which they were
removed.
6. Follow FILLING instructions to restore hot water service.
• Check for water leaks around elements and proper op-
eration when heater is filled.
• Close the front panel.

TEMPERATURE-PRESSURE RELIEF VALVE TEST

It is recommended that the Temperature-Pressure Relief Valve
should be checked to ensure that it is in operating condition every
6 months.
When checking the Temperature-Pressure Relief Valve operation,
make sure that (1) no one is in front of or around the outlet of the
Temperature-Pressure Relief Valve discharge line, and (2) that the
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 temperature-pressure relief valve, lift the lever at the
end of the valve several times. See Figure 14. 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
(page 34). Replace the Temperature-Pressure Relief Valve with
a properly rated/sized new one. See Temperature-Pressure Relief Valve
Test (page 36) for instructions on replacement.
Figure 14. Testing the Temperature-Pressure 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 Water
Systems (page 13) and 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.
36
Explosion Hazard
• Temperature-Pressure Relief
Valve must comply with ANSI
Z21.22-CSA 4.4 and ASME code.
• Properly sized tempera-
ture-pressure relief valve must
be installed in opening
provided.
• Can result in overheating and
excessive tank pressure.
• Can cause serious injury or
death.