SECTION 4 -
APPLIANCES AND SYSTEMS
4-12
PRESSURE-TEMPERATURE
RELIEF VALVE
On occasion, water may be seen seeping from
the water heater pressure temperature relief
valve. This is no cause for repair or replacement
of the valve.
Normally there is an air gap at the top of the
water heater tank, which acts as a pressure buffer.
In time, however, heated water may expand and
fill this air gap, causing a slight increase in water
pressure. This may cause the P-T valve to “weep”
until the air gap is manually replaced.
To Replace the Air Gap:
1. Turn off the Water Heater switch and
incoming water supply (city water and/or
demand pump).
2. Open a faucet in the motorhome to relieve
water pressure.
3. Pull the handle of the P-T valve straight out
and allow water to flow until it stops.
4. Let the handle of the P-T valve snap shut.
5. Close the faucet and turn on the water supply
before switching the water heater on.
Manually operate the pressure temperature
relief valve at least once a year.
NOTE: If your water heater is equipped with the
motoraid system, it uses an extension
from the engine cooling system to heat
water in the water heater while driving.
The engine cooling system must also be
cold before opening the pressure-
temperature relief valve. See “Motoraid
Water Heater” for more information.
NOTICE
Any leak in the heat exchanger or its
supply or return lines could cause loss of
coolant and subsequent engine failure.
We recommend that you periodically
inspect these connecting lines and the
heater to insure that no leaks have
developed.
Water Heater Exterior Service Access
-Typical View
CAUTION
Hot water can escape from tank causing
injury. Operate this valve only when the
tank water is cold.
• Lift handle straight out to open P-T valve
when water heater is cold
-Typical View