Atwood Furnace not staying lit

[Road Warrior 241]

I have a 2018 Jayco 29.5 BH with an Atwood Furnace, been working great until now, when the thermostat is turned on, the fan starts, the burner lights and stays on about 5 seconds then the burner goes out, it will recycle about every 30 seconds, but the burner never stays on more than a few seconds. Limit switch or sail switch? Also how in blazes do you access the furnace controls? The furnace is under the steps in the back bunkroom. Anyone know a good mobile repair service in Orlando area?

[Rustic Eagle]

Symptom described could be a number of things (ie; LP supply, regulator, sail switch, high limit switch, restricted cold air return, etc.).

Unfortunately to access the sail switch, high limit switch, circuit board, etc., the furnace has to be pulled away from the interior wall and/or removed (first remove outside exhaust port assembly)....., since there isn't an outside wall access panel exposing the electrical/gas components.

The furnace reset switch is located on top of the furnace metal enclosure (remove wood box cover if it has one).

Maybe a member will chime in with a local mobile tech service.

Bob

[jetlag]

Originally Posted by Road Warrior 241

I have a 2018 Jayco 29.5 BH with an Atwood Furnace, been working great until now, when the thermostat is turned on, the fan starts, the burner lights and stays on about 5 seconds then the burner goes out, it will recycle about every 30 seconds, but the burner never stays on more than a few seconds. Limit switch or sail switch? Also how in blazes do you access the furnace controls? The furnace is under the steps in the back bunkroom. Anyone know a good mobile repair service in Orlando area?

I had a similar issue with our '21 Pinnacle. It would do this 3 times and then give me an error code. it did say to wait at least an hour before resetting and trying again which I never did, lol. You could check the sail switch for junk on it as yours is a bit older than ours. I took mine out and it looked new as it should since it had never been used. I then thought it was the board and almost replaced it. A couple of days later I tried it again, and it worked perfect. That was 3 weeks ago, and it is still working great. My take on the problem, that someone else here mentioned, is that I had switched gas tanks and might have opened the valve on the new tank a bit too fast. it allowed enough gas to run the stove. This same person said the furnace needs a lot more gas, and why it might be doing what it did. That is all I can figure, as I called the dealer as well as a mobile repair place. We just spent a week in Wilmington NC, and never had a chance to use it as temps were in the mid 70's!! I did run it one day just to be sure, and it is doing it's thing.

[Rustynuts]

Most likely the high limit switch or the the igniter/flame sensor.

[Road Warrior 241]

Thanks Rusty, I bet your on point, getting to it will be the rub. Headed to Orlando, so hopefully will be able to get by on Electric heat for this trip.

[JFlightRisk]

We have a 'sticky' in the Jayco Maintenance and Repair thread, with member recommended mobile techs alphabetically by state here:

https://www.jaycoowners.com/forums/f...ans-79772.html

We don't have any listed in Orlando specifically, but there are three under Florida.

This tech in Washington state has a bunch of very informative videos he's made on RV diagnostics and repair. Check out this site, add it to your favorites if you wish, it may help now or in the future. He gets to the point without the usual 10 minutes of chat in the beginning.

[Thomson]

I have been having a similar problem for the past week. The furnace would start running air then off. Run air run a few seconds then nothing. I am running the furnace right now by resetting the thermostat. Pull the fuse on the thermostat. Count to 20 and replace. To reset the furnace pull its fuse and leave it out for at least t 10 minutes then replace. Not an elegant solution, but at least we are warm.

[Texasnick]

I know a lot of members have provided good recommendations as to what the problem could be preventing the burner to light. I just had the same problem and removed the unit (located under a kitchen cabinet) so I could trouble shoot. I did remove and check the sail switch and did clean the contact area between the switch and sail. It was clean. Here is the thing I found...When I reinstalled the unit, I found a wasps nest in the exhaust tube. It was obstructing the exhaust gas I estimate it reduced the volume of the exhaust pipe by about 25%. I removed the wasp nest, cleaned the pipe and unit works perfectly now. After a long summer not using the furnace, checking for any obstruction in the exhaust pipe is a simple first check and probably should be in everyone's preventative maintenance list. Hope this helps

[Jim Smyth]

I have a 2018 28.5. Different but maybe similar enough. I fought heating issues for a while till I found this video. Havent had issues now for a long time after the mod.



https://www.jaycoowners.com/forums/f...ace-69588.html

[Topperace]

That's why I am a stickler for using the screens over any vent that I can...
so far so good after two years on the road w/ no insect "nests" yet...

[Road Warrior 241]

Thanks everyone for the tips, I was able to access the furnace under the Bunkhouse steps and view the LED to determine which fault to correct. With the aid in the future of a Dental mirror, I will be able to view LED without removing the furnace.

But I found something interesting. My furnace only has one duct connected and it goes to one wall vent, no other connections even though I have floor vents and a heated basement.

Please see pics

The rear Furnace pic is a view of the only duct that is attached to this furnace. The next image is the front return air/ access and the other pic is the only vent attached to the pictured duct. When the furnace runs, It seems I am getting airflow through the floor vents, where is it coming from?

[SmokerBill]

There's a duct connection on the underside of the furnace. I found this Atwood training manual just now. Lots of info.
https://myrvworks.com/wp-content/upl...ing-Manual.pdf

[Rustic Eagle]

Road_Warrior,

I assume the step panel you removed had cold air return louvers. The louvers on your furnace enclosure (reference your pic in Post #11) are for the blower motor receiving the return cold air.

As mentioned, below the furnace there is an opening in the floor exposing a large duct that directs the warm air to the main floor duct and associated floor vents.

My furnace floor opening:



I would remove the floor vent covers and using a flashlight & mirror access each floor vent opening confirming that the main floor duct doesn't have any restrictions or loose debris within the main floor duct.

Bob

[Road Warrior 241]

You were right, the furnace sits on top of an opening in the platform that connects to the underfloor vents. The connection did not seem very airtight considering the furnace compartment is partially open to the rear storage area?? When I replace, I will add some ducting tape to get a more airtight seal.
The LED on the circuit board is not flashing any error codes, But I am ordering a new limit switch just as well. The one I took out is showing continuity so unless if faults with just a little heat ( the burner lights for about 5 seconds ) , It may not be bad.

[Parrott]

Great video for trouble shooting.

https://www.youtube.com/watch?v=0t8vRuGdZLw

[TGoldsbury]

Mud dauber nests gave me the intermittent run problem, make sure to get screens.

[MSG Coons]

just like any other furnace, check the flue....exhaust vent.

[David2425]

The furnace will not attempt to light if the sensor or flow switch is bad. Those two safety devices have to be happy before the gas valve will open.

My furnace would attempt to light three times then shut off and give a little puff of smoke. A little heat would come out for a second or two. I found that my circuit board was wet. I searched YouTube and found someone with the same issue. That person suggested contacting Dometic. So, I contacted Dometic and they are sending me a replacement board with an adapter that is supposed to prevent this issue from recurring. When I purchase the RV (used) the dealer had to replace this board but I didn't know why it went bad. Now I know it was an engineering / manufacturing defect that leads to the failure.

They need the VIN, model number of the furnace, name, address and phone number.

[videoarizona]

I'm in total agreement with Topperace. I have screens on fridge, heater and water heater. 3 years and no wasp or critter issues!
Cheap and easy to install.

[Parrott]

Originally Posted by David2425

The furnace will not attempt to light if the sensor or flow switch is bad. Those two safety devices have to be happy before the gas valve will open.

My furnace would attempt to light three times then shut off and give a little puff of smoke. A little heat would come out for a second or two. I found that my circuit board was wet. I searched YouTube and found someone with the same issue. That person suggested contacting Dometic. So, I contacted Dometic and they are sending me a replacement board with an adapter that is supposed to prevent this issue from recurring. When I purchase the RV (used) the dealer had to replace this board but I didn't know why it went bad. Now I know it was an engineering / manufacturing defect that leads to the failure.

They need the VIN, model number of the furnace, name, address and phone number.

If your furnace has an outside access panel then water or moisture can be a problem. The panels are hard to waterproof and the board relocation kit helps. Does yours have an outside access panel?