Into the weeds with an Atwood Furnace

[Bob T]

As I detailed recently, I was able to remove my furnace motor (an 8012) from the 17' Bigfoot and lube it successfully getting rid of an awful squeak from the bushings.

Of course, things never go so easily. I appear to have two outstanding issues that may or may not be linked.

On extended usage ( a few hours), the furnace didn't re-light when trying to come back on (its a pilot version). I was able to be there at another test period when it tried to relight, and noticed the pilot was no longer on. The fan function is fine and comes on when commanded. I think the pilot goes out after some delay, because I have been able to do a restart immediately or a short time after shutdown.

I detailed about a week ago, that the motor in my unit has been previously replaced by someone, with one that fit, but its a significantly higher amperage at 2.8, that what the furnace is meant to have (1.6 amp motor). This probably throws more combustion air than is needed to the burn system and its orifices (air/gas) which does who-knows-what.
My Hydro-Flame manual, notes this: "low microamps can be caused by too much combustion air". But I also note that statement us under the section for Direct Start Ignition System - of which mine is not. Sooo, I have no clue if that is relevant to a pilot system, or the burn system itself??

My second, related or not, issue is that my burn flame is decidedly orange, and not the desired blue. Its not a 'lazy yellow' which is another symptomatic indicator of other things. My pilot is pure blue.

I've played around a bit with the pilot adjust screw, and another adjust screw that I think is labelled 'vent', and haven't really noticed any difference in the colour of the burns. I even tried mostly blocking off the air intake holes at the outside of the trailer to see what that would do...again, no perceivable change.

I know I should remove the pilot tube and clean, along with any other bits sitting out in the flame path.
I will also order a new 'correct' motor, so that I take that unknown out of the equation.

At this point, I'm at the limit of any knowledge of how to fine tune this thing, but for now I can get heat if and when I need it anyway. I don't think anything is amiss with the thermostat or sail switch, or venting.

Doing an overnight mid-week, but will have a ceramic heater along for back-up

Bob T.

[Stevieboy]

Sounds like you have a plan. Clean the tube and get the right motor. Even if that doesn’t help you’ll have a clean tube and a new motor !

[Kenny Strong]

Bob
My 93' Atwood heater. squeals, at start up. then quiets as it gets warm. the pilot will not light if I have a low battery. the fan motor comes on and can run for ever, but pilot will not ignite. hook up trailer to the toe and charge the battery the pilot will ignite.
In the past; battery well charged, plenty of gas I have turned the thermostat on and set the temp gauge to come on. pilot would not come on, fan motor running. I moved the manual lever back and forth turning the power on and off, on and off, on, the pilot will light. I bought a new Atwood thermostat, I have to do the same thing with it, to get the pilot to work. once the unit is hot, it will work on its own accord.
I have had friends suggest I buy a new digital thermostat. ???? where I turn the manual thermostat on and off and on, giving the pilot light assembly a jolt of power; will the digital just come on ? ( I don't know, the names of the associated electrical parts ) Do I need to replace a coupling device; what ever it might be called ?
Wish You success.
Later Kenny

[Bob T]

thanks for the replies..
Kenny, I don't know enough about the electronics to comment on what you are experiencing but maybe someone else can chime in. In my case, it seemed the pilot was being 'blown out' when it started to restart itself after the first heat cycle.

UPDATE
So we went for an overnighter last night in Parksville, Vancouver Island. It was chilly overnight, BUT the furnace worked like a champ, and kept us warm all night (and never a squeal either. I did make one simple adjustment before the trip that may have cured my problem. I turned the pilot adjust screw out a turn and a half just to see if that would add a little gas flow and strengthen the pilot. Visually you can't tell, but it never went out once.....so here's hopin'

Bob T.

P.s. I wrote earlier that my burn flame was orange. It doesn't seem to be a sooty or smokey exhaust, and I can't really get a good look at the flame through the tiny viewing hole, so maybe I'm over-analyzing this.