Water heater won't heat

[John Greenlee]

Hello all,

I just got home today with my second Airstream. A 1966 Overlander. Beautiful trailer.

My challenge.... I can light the pilot o.k. on the water heater. However, it does not kick on to produce any hot water. In other words, the main burner never lights. Wassupwidat? The pilot just goes on and on....

Can it be a thermo couple or is the control unit necessarily bad?

Thanks,

JMG

[StingrayL82]

I would check for any obstructions in there first. From what I hear, muddaubers and those little propane inhaling spiders love it in there.


Frederic

[nickcrowhurst]

John, this was discussed about 18 months ago at this thread:
http://www.airforums.com/forum...20&highlight=%
I hope it contains a few pointers for you.
Nick

[John Greenlee]

This doesn't seem to be exactly my problem. My pilot burns and burns hands off, but the main burner never kicks on. I wonder if a thermocouple affects this?

JMG

[overlander63]

Originally Posted by John Greenlee

This doesn't seem to be exactly my problem. My pilot burns and burns hands off, but the main burner never kicks on. I wonder if a thermocouple affects this?

JMG

Sounds more like a thermostat. You may also have a restriction in the gas line, although I would think that would cause the thing to go out after the main burner tried to light, and starved the pilot for fuel.
Have you tried moving the thermostat setting around at all? Maybe set it higher than you would want, then throttling back when the burner lights off?

[brunoffrance]

Hi there,
I've replaced my water heater system this summer by a new ATWOOD thermostat, pilot, burner... excep the tank.
The pilot was OK like yours and the thermostat began to produce fire to heat water and suddently stop each time after a few seconds.
ATWOOD says it was a bad model and the default was the couple inside the thermostat and they send me another one;
I suppose if this kind of part, even if it 's a new one can be wrong, the genuine one in your 66 Overlander is out with the time.

Change only, like me, all these parts and keep your genuine tank.

Bruno.

[85MH325]

John, it may very well be a total obstruction of the burner tube. Those spiders are pretty pesky. I've got two trailers and had small spiderwebs in each of the burners so far this year. Both of them were small partial obstructions, just enough for the flame to be yellow and sooty.

At last years' Midwest Rally, the water heater wouldn't light on a brand new 19' Bambi. The pilot was fine, but no burner. I pulled the burner off and found a spider web totally obstructing the tube. Cleaned out the web, and it was good as new. I'd recommend you check your burner first. If you find a web in it, a bottle brush or a straw, or even a flexible stick will work.

DO NOT run anything hard through the brass orifice. If you think it needs to be cleaned, use nothing harder than a piece of fishing line. If you do, you'll be buying a new orifice real soon.

The thermocouple only affects the pilot light. Of course, the burner won't light either if the thermocouple is cold. If you have a pilot that stays on, your thermocouple is fine.

Roger

[John Greenlee]

Well, I replaced the thermocouple and checked the burner tube. It is not obstructed. (the orifice is pretty small isn't it?) I am thinking the control unit is bad. Is there a replacement available? Mine has the original Honeywell unit from 1966. I researched using a household propane control unit, but decided it will not work -- at least because of the odd size left hand threaded outlet for the burner.

Are there new control units available?

Thanks,

JMG

[stagecoachbill]

Make sure you have make, model #for water heater.I got parts for my 69 Atwood from www.marksrv.com. Watch for yellow highlight about parts. I just bought hte complete burner unit which includes the pilot light, thermocouple and burner tube.
Hopefully you can find the parts you need.