Furnace Will Not Ignite

[peterg5326]

Our furnace has quit working in our 2020 27’ Globetrotter. It’s not the sail switch- we’ve replaced that a year or two ago and we’ve checked the one being used. There’s no debris on it and our electrical meter shows it working exactly as it should. There is a switch reading “off/reset” and we turned it off then back to reset (“reset” is the position the furnace runs in). At first the furnace started up correctly (after purge the furnace ignited and ran properly). Then after we reassembled the covers it once again didn’t work- runs purge but never clears to ignite. So we are thinking the control panel is bad. Has anyone on this group had similar issues and what was your fix? Any and all ideas welcome, thank you for you help!

[Daquenzer]

This may be a dumb question: Have you tried other gas appliances?

If you have, and I assume so, you may need to take this in to a repair place. Doesn’t have to be an Airstream dealer. In fact a decent furnace repair person probably could get it fixed for you.

[peterg5326]

Yes, the other gas appliances work (stove, hot water heater).

[GCinSC2]

Furnace model number?

[Daquenzer]

Originally Posted by peterg5326

Yes, the other gas appliances work (stove, hot water heater).

Is it getting ignition spark? It seems odd that a 2020 furnace should have that many issues.

I might try to get to the furnace and make sure all the connections are tight (no lose wires).

[WhatNext]

The flex hose feeding propane to the furnace on my 2022 got kinked.

[link2dks]

I had similar problems on my 2019 27 GT. I cleaned the sail switch, which did not look dirty and could get the furnace to work but only intermittently. I ended up replacing the control board with a Dinosaur control board, problem fixed.

Dave S

[keepontravln]

We had that problem with our '72 Sovereign while camping in New Mexico. After checking electrical connections, propane and thermostat, I finally read the furnace owner's manual where I discovered that our furnace has a safety feature which prevents ignition when there is not enough oxygen to support operation. Simple fixes: add layers of clothing, use electrical heating or relocate to a lower altitude. keepontravlin

[Pat Pierce]

The first night on our first of the year roadtrip, we discovered our furnace wasn’t working (and it may not have been working for some time). Looking at the furnace manual, it said to look at the blinking red lights at the control board, and from the lights seen, that gives a clue to the problem.

Fortunately, we were close to a AS dealer, and were still under extended warranty.
They accommodated us and spent a few hours mostly bending, rebending the sail switch in a jig designed for the purpose. Closing time, and they allowed us to spend the night in our trailer with shore power. The next morning, they spent a couple more hours, deciding to try replacing the control board…and the new one has been working ever since (about 4 years later).

[tgoedken]

Peter - I have a 2019 Globetrotter 27FB, with an Atwood AFMD25 model furnace. Mine just went out last night and have another post asking the same questions. Did you ever gets yours fixed?

Tom

[s1000pre]

I just fixed my barely used furnace on my 2021, the ignighter was bad.
Symptoms:
The furnace would start and run for 15-20 minutes, then turn off before reaching temp. Once it turned off, it would not re-ignite.
Let me know if this sounds familiar, I can walk you through replacing...its fairly easy.

I have a Dometic DFMD30111, the igniter & board are below, if you have the same model.

Hydro Flame 35100 Electrode for... https://www.amazon.com/dp/B016MWVNY6...p_mob_ap_share

DOMETIC 31501 Dc Furnace Circuit https://www.amazon.com/dp/B01KHLH77K...p_mob_ap_share

[jclaypoo]

I have a 2023 International. Furnace wouldn't start & had to take it back to the dealer. Sail switch was faulty.

[XCountry]

I have had this problem several times, and every time it has been the sail switch. Not fun in the middle of a cold night or in the rain.

Those are very finicky and in my case I was never about dirt, the blade is very close to the fan’s external housing and contact between the blade and the housing can interfere with the switch getting pressed.

I’ve had to kink my sail switch slightly to keep it away from the housing to address this, and it’s worked.

[peterg5326]

The model number is AFSD20111.

[peterg5326]

Originally Posted by gcinsc2

furnace model number?

afsd20111

[peterg5326]

Originally Posted by tgoedken

Peter - I have a 2019 Globetrotter 27FB, with an Atwood AFMD25 model furnace. Mine just went out last night and have another post asking the same questions. Did you ever gets yours fixed?

Tom

I changed the circuit board and the problem remained. But I got a hint I’ve not tried yet- because strangely the furnace is working now. The hint I’ll pass along is a weak ground connection. This might make sense-the ground connection is right in front of the fan and above the circuit board on my model and the ground wire and other circuit board wires are pressed when the hatch is screwed on. This could explain why our furnace would run when the hatch was off- if the ground was loose perhaps then was making connection. We are limping home and I intend to check this connection and all other connections well once settled, but hoping this continues to work these last few days of traveling.