Water heater not staying on

[revkaruna]

1996, 28' Excella
I live in my trailer and shut of the hot water heater for a few days while I was away. There is a fill LP tank, and the gas is getting to the hot water heater. When I turned it back on, the ignition lights the heater, the fire comes on, then after a few seconds it goes off, and the light is red (like it is when it is out of gas, except I know there is gas). I don't know how to fix these things. Any suggestions.
Thanks.

[Protagonist]

First a dumb question… Are you sure there's water in the heater? You mentioned propane and spark, but not water.

Then some speculation… Could be a faulty thermostat. I had a faulty thermostat on mine, that wouldn't shut off the flame until the water was almost boiling, leading to a red fault light from overheating. But it's possible for it to fail the other way, shutting off the flame while the water is still cold.

I didn't replace my own thermostat, so I can't tell you how it was done. In my case, it was a warranty issue, that cropped up on my very first camping trip in my Airstream, so I wasn't about to let Airstream off the hook by fixing it myself.

[RamblinManGa]

Hi from AZ. . . in most water heater applications, a thermocouple is used to allow gas valve to open if it's hot. Sounds like your thermo is bad. Pretty easy replacement, make sure the pointy end will be IN the flame...... good luck, Regards, Craig

[Skater]

Thermostats are super easy to replace - they just twist and pop out. They (and the ECO) are cheap enough that you might throw new ones on just to test, but I'm not convinced that's what's wrong with yours. A bad thermostat usually means it would still "work" - it wouldn't turn on the red light. In your case, obviously the electronics have decided something is amiss, and it's turning on the red light.

I think I'd go out and watch it (with the door open, but stand back in case something weird is going on) to see what it's doing while someone turns on the switch inside.

[yve79]

We replaced our thermostat and several other things to no avail. Started doing something similar after we had it polished and had everything turned off for a month. Finally we replaced the water heater. Surprise, surprise the new one did the same things. So finally we blew out the gas lines. It was getting enough gas to turn on and heat somewhat sometime but not enough to work properly because of crud buildup while it sat. It works perfect now.

[revkaruna]

Gosh, thank you all so much for your help and so quick!! I think I'll start and replace the thermostat. I'll let ya'll know how it goes!

[RamblinManGa]

Hi from AZ. . . I was talking about thermocouple, not thermostat. F Y I , regards, Craig

[Dan and Liz]

yve79: never heard of such a thing as crud in gas lines, but that might explain the issue we've had. Any advice on blowing out the lines --just a good blast of compressed air, or (?)

[7GenTex]

"Hot water heater"?

[Protagonist]

Originally Posted by Dan and Liz

yve79: never heard of such a thing as crud in gas lines, but that might explain the issue we've had.

"Crud" covers a lot of territory. The compartment isn't sealed, so there may be road grime, blown dust, spiderwebs, the remains of a wasp nest that never quite got built, you name it.