Pilot lights, but shuts off when turned to "on"

[Becky B.]

I'm camping with my daughter. She has an argosy with a 1 year old Atwood water heater. She can light the pilot light & it stays lit. As soon as she turns it to "on" , the whole thing shuts off. Any ideas?

[idroba]

I would first try to clean the burner tube on the main burner. It is common to get spider webs in it, and then when the main burner is turned on, the gas/air mixture is not ignited but actually blows out the pilot light. Sounds strange, I know, but it has happened to me. Also try to run something up through the tube that goes through the water heater, if spider webs are there, a similar thing can happen.

It sure could be something else, but in the field, that is what I would try first.

[Ganglin]

MAIN BURNER WILL NOT IGNITE

Blocked main burner orifice

--------------------Clean or replace orifice
Main burner flame spreader mis-alignment --Square flame spreader to end of main burner
Blocked main burner ----------------------------Remove blockage
Improper air adjustment ------------------------Adjust main burner air shutter approximately 1/4 open
Blocked “U” tube --------------------------------Remove blockage
Gas control out of calibration ------------------Replace gas control

[Mikethefixit]

Even though the heater is only a year old,the first thing I would do is change the thermocouple. They go bad at any age. Then I would work from there. Go thru Ganglin's list. GOOD LUCK

[Becky B.]

Yes, we are all blondes....... The gas valve under her trailer was knocked shut! I forgot she even had one, but after going through some suggestions, I called my DH, who has a memory like a trap, and that was the first thing he suggested. Now I can rest assured that my shower is still my own! Thanks all, for all the suggestions---much appreciated!