Water Heater Pressure Valve

[jjh81vette@comcast.net]

On a recent trip I experienced the following problem: hot water was leaking out of the pressure valve located on the outside of our coach near the water heater. I have a water pressure fitting on the hose which is connected to city water.I turned off the city water and used our holding tank...the leak stopped but my water pump was acting different.....a constant humming sound came from it. Any suggestions for an easy fix? Jim

[wolfe10]

Welcome to the FMCA Forum.

This is likely two separate issues.

It sounds like you have a pressure reducer on the shore water-- an excellent idea.

1. You may have lost the air cushion in the top of your water heater. Water (like everything else) expands as it is heated. If there is an air cushion, the air absorbs the PSI increase. But if no air cushion, the PSI has to go somewhere-- water isn't compressible!

To reestablish an air cushion open the pressure valve (flip the lever) and a hot water faucet (with shore water and on-board pump OFF). That should siphon the water down and reestablish the air cushion.

If a Suburban water heater and you have not replaced the anode in over a year, removing and replacing the anode will also reestablish the air cushion (along with doing recommended maintenance).

And if an Atwood water heater, removing the plastic plug (and replacing with another Atwood plastic drain plug) and flushing the crud from the bottom of the water heater will also accomplish the same thing (along with doing recommended maintenance).

2. The pump should not be making noise all the time-- only when pumping. Are you sure it is the pump? If you can reach it, put your hand on the pump. Verify that it IS running (vibrating). Also, from a danger standpoint, verify that it is not hot. These pumps are water cooled (from the water flowing through them. With no water flow and continuous running, it could be a fire danger.

Brett