The single propane furnace is my 1998 U270 is not working properly. It stinks of combustion gases (not a leaking propane smell) and has black soot on the exhaust tube visible both inside and outside. I pulled the outside cover and did not see any obvious obstruction in the tube or squirrel cage fan that draws in combustion air. I pulled the inside vent cover but couldn't see anything of note. I've used it a lot since November, but for two weeks had good 50 amp power and used the rooftop heat strips. Was mooch docking with 15 amp power, went back to the Atwood furnace and the next morning it was stinking up the driveway. CO detector, which is new, did not go off. My local RV tech is booked up through the month and everybody in the county is having furnace problems. Moved to new site with good 50 amp power, running coach on electric but it is really getting cold over the next 10 days here in North Texas.
Suggestions welcome for how to proceed.
It looks like your air mixture is off and you are generating a lot of soot. If not, you may have a crack in the chamber as it could do the same thing. You would get the smell of combustion, but it may not be enough to set off the C02 alarm. Can you access the chamber and take a look at it? Hope this helps! Good luck!
Try pulling up Atwood help center and see what they say to look for.
I had a furnace in another motorhome that was doing that. I pulled out the exhaust tube that looked like yours and cleaned it up with solvent. Sometimes mud dobbers can get in there also.. It doesn't take much restriction to cause problems. The tube is usually just held with a single bolt behind the outside cover.
Good luck with it
Larry
You might have a dirt/mud dauber nest that is in the combustion chamber tube as it looks like you don't have a bug screen. Take a wire cloths hanger and straighten it out. Use this to gently probe in the exhaust side to see if you can fish something out. If nothing then joe is on the other track.
Mike
I concur with Joe , had the same issues with mine, pulled it out took it completely apart and found cracks in the chamber, had it tig welded put it all back together and it worked for a short time but could still smell it, so I replaced it with a OEM.
See if the trouble shooting section is of any help?
RV Products 8535 SERIES Service manual | Manualzz (https://manualzz.com/doc/991037/rv-products-8535-series-service-manual)
Looks like you may need to rebuild the burner and igniter area,couple of places sell kits to do this,think if the exchanger had the crack it would not be causing the soot,while your in there get a new fan motor,yours will be screeching soon.
The burner assembly is no longer made and out of stock in all the usual places. Not good. If I tear into this and the burner is bad I will have to find a replacement. The domestic somewhat equivalent also appears to be on back order. This could turn into a a major retrofit project.
Patrick,
What part number are you looking for and finding out of stock? If it is "Burner 32811" then I might be able to help.
See Reply #6 in the thread linked below:
Need Hydro Flame Furnace Burner (https://www.foreforums.com/index.php?topic=23119)
I installed the burner I got from Amazon 7 years ago and it is still working perfectly (AFAIK). In fact, it has been cycling on and off all day today cuz it is 19 degrees here. Tomorrow it will supposedly hit a low of -3 degrees F :o so I'm sure hoping both our heaters continue to function.
Amazon.com: Atwood 36043 Burner: Automotive (https://www.amazon.com/dp/B004QMYYF0/ref=pe_385040_127541850_TE_item?ie=UTF8&tag=foreforums-20&linkCode=as2&camp=1789&creative=390957)
I am looking for that elusive 32811! I'm currently hiding out in Galveston from the -2° forecast in North Texas. When it warms up I'm going to tear into the furnace and if it is the burner then I'm going to replace the burner, fan motor, and control board.
So long as heat exchanger looks okay.
The reviews on the newer furnaces are not very encouraging.
Thanks for responding.
Please double check for carbon monoxide from the heater. Make sure all detectors are working properly! Please post your findings as well. Stay safe!
While you have it all torn apart, check the condition of the spark and temp sense electrodes. Clean (if necessary) and adjust gap to 1/8".
See page 25 in the manual I linked above (Reply #5)
Just a FYI, if you hit a dead end on parts try this guy, Tristate RV parts. 517-448-4433.
I got a OEM new in the box for around 600 bucks shipped.
I'll check them out. Thanks for the suggestion. Their website is down at the moment.
Thanks for heads up Joe.
When it comes to Carbon Monoxide, we have redundant detectors in the bedroom and some other locations.
They are inexpensive battery operated with digital displays.
Much more fun to not wake up dead from our CO or a from a neighbor's CO.
Seems to happen too often and is fully preventive-able.
Update: warmed up enough to mess with furnace. Flu pipe was the happy home of mud dobbers. Removed it, cleaned it out and furnace is better. Also learned that my paperwork on the furnace was inaccurate. My data plate says Atwood 8940 iii dclp. Will dive into it further when back to some place I can receive parts. I'm going to pull burner and motor for deeper assessment when a bit more settled. I suppose this falls into the category of owner neglect/ignorance.