Atwood furnace

[TexAirS]

We have the Atwood 8535-IV furnace in our 2001 Classic. It lights most times and makes an awful racket most of the time. At 18 years, it's time to replace.



Go with a new Atwood, Dometic or some other brand?


Thanks in advance,


Sjohn

[perryg114]

It probably needs cleaning. They get full of bugs. If the heat exchanger is not cracked they will last a long time. I just rebuilt one and it was completely stopped up with lady bugs, mud dauber nests, and no see um in the burner jet. If a bug made a nest across the electrodes that could mess it up. I am not saying it does not need replacing but that would be the quickest if you are flush with cash and don't want to mess with it.

HEre are some manuals for it.

https://techsupport.pdxrvwholesale.c...twood-8535-iv/

Perry

[PeterH-350LE]

Originally Posted by TexAirS

We have the Atwood 8535-IV furnace in our 2001 Classic. It lights most times and makes an awful racket most of the time. At 18 years, it's time to replace.
Go with a new Atwood, Dometic or some other brand?
Thanks in advance,
Sjohn

I dont think you would want to change the existing cutout for the Atwood 8535, so Atwood shoiuld be your first choice.
The replacement is Atwood

Model AFMD35
Approximate Casing Dimensions 16 1/2" W X 7" H X 20" D.


Last I checked, it is a couple inches deeper than the original, so make sure you verify your usable space.
Like Perry said, other than Mud dauber etc problems, they are tough little machines and most everything can be cleaned, adjusted and worked on.
I cleaned a lot of mud dauber nest all over my 8535II and also replaced the circuit board and the limit switch. Spent a fraction of the 800.- new cost and have perfectly quiet running furnace.

[perryg114]

Well they are not quiet on a good day but they should not make buzzing or rattling noises. They will sound like a big hair dryer. Mud daubers can make a nest and put the fan out of balance. New or old put a screen on it to keep bugs out. Lady bugs are bad here. They get in everything.



Perry

[TexAirS]

Thanks for all the info. I was afraid the newer units would be larger or worse, smaller. I have cleaned out the mud dabber debris and it lights most times. The scenario this fall was, when its 17 degrees outside and 46 inside, we hope it lights this time.


Time to take it apart.


The main concern is the occasional screeching. Bearings in the motor or squirrel cage? I have grown to appreciate the 'normal' noise the furnace makes.


Sjohn

[PeterH-350LE]

Originally Posted by TexAirS

..... Bearings in the motor or squirrel cage?
Sjohn

Access to the fan and motor is the easiest of all furnaces. Move a few wires , 4 screws and the cover comes off. Sometimes the circuit board needs to be moved as well.
I noticed that the motor and attached fan location is held into place by 1 wimpy screws, which could easily cause movement of the assembly resulting in contact to the housing.

[75Bob]

I don't know where you camp, but if you head for mountains even in the summer months it gets cold at night. If you are in an elevation above 8,000 feet, propane does not want to lite. I found that out from people that stay at that elevation. They bring a electric heater as a back up and lent me one so we wouldn't freeze.lol

[TexAirS]

We camped anywhere from sea level to almost 9,000 feet this summer. The altitude was in NV, UT, CO and NM late fall. Lows were 18 outside Moab without hookups in Horsethief CG. 17 degrees in Taos (love the place) with hookups. We use a 1500 watt electric heater to supplement the furnace when possible. Black Canyon was 24. Santa Fe was 25. Daytime temps were in the 50's. No freezing of the pipes.



But I wonder if we could have been between a rock and frozen pipes if the the furnace had not lit or the squirrel cage had stopped.



Time to take the furnace apart, clean and see what is squealing.




Sjohn