Rheem Gladiator Use & Care Manual page 7

A new combination temperature and pressure relief valve, complying with the Standard for Relief
Valves and Automatic Gas Shut-Off Devices for Hot Water Supply Systems, ANSI Z21.22, is supplied
and must be installed in the opening provided and marked for the purpose on the water heater. No
valve of any type should be installed between the relief valve and the tank. Local codes shall govern the
installation of relief valves.
! WARNING: The pressure
rating of the relief valve must
not exceed 150 PSI, the
maximum working pressure
of the water heater as
marked on the rating plate.
! WARNING: The tank
must be full of water before
heater is turned on. The
water heater warranty does
not cover damage or failure
resulting from operation
with an empty or partially
empty tank.
Relief Valve
The BTUH rating of the relief valve must
not be less than the input rating of the
water heater as indicated on the rating
label located on the front of the heater
(1 watt=3.412 BTUH).
Connect the outlet of the relief valve
to a suitable open drain so that the
discharge water cannot contact live
electrical parts or persons and to eliminate
potential water damage.
To Fill the Water Heater
Make certain the drain valve is completely
closed.
Open the shut-off valve in the cold water
supply line.
Condensation
Condensation can form on the tank when
it is first filled with water. Condensation
might also occur with a heavy water draw
and very cold inlet water temperature.
Piping used should be of a type approved
for hot water distribution. The discharge
line must be no smaller than the outlet of
the valve and must pitch downward from
the valve to allow complete drainage (by
gravity) of the relief valve and discharge
line. The end of the discharge line should
not be threaded or concealed and should
be protected from freezing. No valve of
any type, restriction or reducer coupling
should be installed in the discharge line.
Open each hot water faucet slowly to
allow the air to vent from the water
heater and piping.
A steady flow of water from the hot water
faucet(s) indicates a full water heater.
This condition is not unusual, and will
disappear after the water becomes heated.
If, however, the condensation continues,
examine the piping and fittings for
possible leaks.
7