Temperature & Pressure Relief Valve - Suburban SW10P Service Training Manual

The temperature and pressure relief valve is designed to open if the temperature of the water within the heater reaches
210F, or if the water pressure in the heater reaches 150 pounds. Recreational vehicle water systems are closed systems
and during the water heating cycle the pressure build-up in the water system will reach 150 PSI. When this pressure is
reached, the pressure relief valve will open and water will drip from the valve. This dripping will continue until the pressure is
reduced to below 150 pounds, and the valve closes. This condition is normal and does not indicate a defective relief valve.
Warning! DO NOT PLACE A VALVE BETWEEN THE RELIEF VALVE AND THE TANK.
DO NOT PLUG THE RELIEF VALVE UNDER ANY CIRCUMSTANCES.
Water WeePing Or DriPPing FrOM PreSSure relieF valve
You may experience water weeping or dripping from your water heater's Pressure and Temperature (P & T) Relief Valve
when your water heater is operating. Water weeping or dripping from the P & T Valve does not always mean the P & T Valve
is defective. As water is heated, it expands. The water system in a recreational vehicle is a closed system and does not allow
for the expansion of heated water. When the pressure of the water system exceeds the relieving point of the P & T Valve,
the valve will relieve the excess pressure.
Suburban recommends that a check valve not be installed directly at the inlet to the water heater tank. This will increase
weeping of the pressure relief valve.
One way to reduce the frequency of this occurrence is to maintain an air pocket at the top of the water heater tank. This air
pocket will form in the tank by design. However, it will be reduced over time by the everyday use of your water heater.
To replenish this air pocket:
1. Turn off water heater.
2. Turn off cold water supply line.
3. Open a faucet in the RV.
4. Pull out on the handle of the Pressure Relief (P & T) Valve and allow water to flow from the valve until it stops.
5. Release handle on P & T Valve - it should snap closed.
6. Close faucet and turn on cold water supply; as the tank fills, the air pocket will develop.
Repeat this procedure as often as needed to reduce the frequency of the weeping of the P & T Valve. If the weeping persists
after following this procedure, you may elect to install an expansion or accumulator tank in the cold water line between the
tank and check valve to relieve the pressure caused by thermal expansion. Contact your local dealer for assistance.
PRESSURE RELIEF VALVE
Warning! Do not remove or plug the relief valve.
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