HW Heater Won't Stay Lit with the Door Closed

[Jim Stoltz]

It may be time to replace the 30-year-old HW heater in my Allegro, but I'd like to see if I can nurse it along one more season. There are many other things competing for the $350 it would cost to replace it.

It worked sort of okay last year. It stayed lit, but the thermostat wasn't working properly. It would get hot enough to open the relief valve and/or hit the cut-out switch. I have a new thermostat for it, but now it's not staying lit with the door closed.

With the door open it has a nice strong flame. When I close the door I can hear the flame choke off a bit. The electronic ignition will start to click (I guess because it doesn't think the flame is lit?) and it will eventually die. I assume the flame gets its air through that vent on the front? I cleaned that out last season when I first put the thing on the road because it was clogged with wasp nests. I can't see it being clogged up again.

Any suggestions beyond the vent?

Thanks!

[Rich Thomas]

You've probably done this but make sure all the burner holes and pilot orifice's are clean if it has a therm-o-couple  make sure its clean and adjusted. 

[Jim Stoltz]

Actually I haven't really messed with it at all. I'll check those things out. I was going to try to open up the air holes some more but the adjustment screw has corroded and become one with the tube.

[Rich Thomas]

Ill bet mine's in the same condition. 37 years old and I haven't tried it out yet. Just something I haven't had the need for yet but, I'll probably start on mine soon. I'm wanting to hit a few races this year and plan on camping at the track at least two of them.

[Jim Stoltz]

Mine had been sitting for about 6 years before I got it in late 2013. Inside the door is very rusty, but not rust-through-type rusty. Just covered in it, if you know what I mean. I did have it apart last year but I really don't recall why. I replaced the thermostat with an adjustable one at that time, too. It only works intermittently so the manufacturer sent me another that I've yet to install. I had to replace the relief valve, too, because it wouldn't seal up anymore after the first time it overheated.

Anyhow, I fired it up again last night with the city water hooked up instead (when I posted I was was just using the fresh water tank). I know city vs. tank has nothing to do with it, but the stupid thing worked flawlessly. Stayed lit and shut off when it should. The adjustable thermostat appears to be working when I adjust it, but even on its lowest setting the water is uncomfortably hot, but I guess when you have a small tank you have to keep it pretty hot in order to make it last longer.

Maybe there was air in the propane lines or something else related? I replaced the regulator just before I posted, too, but the stove and furnaces seemed to be working okay. It took a while for the fridge to want to stay lit, though. Hmmm....

[Rich Thomas]

Your probably right on the air in the line. My furnace decided to quit working over the winter. it worked great in November. t's way,way down on my to do list though.I have about 30 yards of concrete to get poured before I can put money into the heater.

[david craft]

I know of 2 venting mods for old WHs but none for the atwood 6 that I see in the pictures.  you could try modifying the lower hinges outward some to allow more air in.  that burner flame should be blue with and outer and inner cone.  adjust air to where shes noisy then close to where she just quiets to a slight roar...if there is such a thing

[Jim Stoltz]

That's pretty much the way it is - the sounds are exactly as you described. It went back to its old ways last night - wouldn't stay lit. It seems ambient temp has something to do with it. 

[James and Yvonne Hoak]

Does your unit have a pilot adjust on the gas valve if it does adjust the pilot flames little higher mine did that I ended up replacing it  I couldnt adjust the flame