That controller actually has the part that goes back into the tank and regulates the run cycle. if it's broken, I don't think I'd mess with it.
Maybe you have an experienced, old propane guy in your area . . .
Years ago, I had a leaking tank in the water heater on my Argosy. Three-Way Campers in Atlanta, who sold the trailer originally, happened to have a dusty, but new tank that wasn't very expensive. My local propane guy replaced the controller for about $50, and that was in 1992.
Faced with a similar problem recently on the Excella, I decided that it was easier to replace the water heater than to repair it. Not only did I get better saftety features, this one has a switch inside to turn on the water heater. That sure beats a standing pilot, and I like the convenience of flipping a switch.
I ordered the water heater from PPL Motorhomes in Texas. They are not always the cheapest I can find on the net, but they've come through for me when I needed specific stuff again and again. Their parts department folks are friendly and are a pleasure to deal with.
In other words, if your controller is shot, you may as well abandon this ancient water heater and put a new one in. You'll know what you have, and it should be good for years of service.
1975 Argosy 28 "Argosy"
1979 Excella 500 31 "Betsy"
1992 Lincoln Mk 7 LSC
2003 Dodge 2500 Cummins "TowHog"
"Lucy Loosehair" the cat - Airstream mascot
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