I have an older American Appliance water heater on my 1985 coach. The burner won't shut off and the pressure/temperature safety valve then does its thing, but it doesn't just "weep," it goes hysterical. Water jets out of the valve as fast as the city water is coming in. I have reviewed all your columns on-line but haven't seen another problem like this. Help!
Jim, (Olympia, WA)
Jim, (Olympia, WA)
Jim, as long as your incoming water pressure is not abnormally high, it could be something as simple as a faulty P&T relief valve. But if your pilot-type water heater is not properly shutting off the main LP burner when the temperature of the water has reached the limit of the control valve thermostat, then that safety valve is operating properly. If you manually shut down the water heater does the P&T valve finally snap shut at some point? If so, than most likely the integral thermostat itself is faulty as well as possibly the ECO (energy cut-off) device encased inside the very tip of the sensor; that portion immersed in the water.There were two types of ECOs used in those older pilot model RV water heaters; one was a bi-metal thermal switch of sorts that should eventually reset itself once the water temperature cools. The other type was electronic by design and will not reset. It's a one-time safety and once it's tripped, there is no way to regain continuity through the device. Chances are the whole control assembly will have to be replaced if the ECO is the culprit.
As old as that water heater apparently is, however, I would consider replacing the entire unit and obtaining a new warranty, etc. The newer models are much more efficient and offer the best in the latest technology. You certainly would not want to invest in a costly repair only to have the inner tank rupture in the coming months. I'd vote for a new unit if it is the main control valve at fault.
