09/06/10

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 does not mean that 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 vale will relieve the excess pressure.

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:

Turn off the water heater.

Turn off the cold water supply line.

Open a faucet in the RV.

Pull out the handle of the pressure relief (P&T) valve and allow water to flow from the valve until it stops.

Release the handle on the P&T valve - it should snap closed.

Close the faucet and turn on the 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 P&T valve. If the weeping persists after following this procedure, you may elect to have your dealer 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.