Furnace Doesn't Maintain Heating Throughout Night

[Etep]

We have a 2021 Grey Wolf 26BRB. Brand new.

Since day 1 we've noticed that the furnace will stop trying to heat the trailer during the night. If I set the thermostat to off, wait a few seconds, I hear a click, then I turn the thermostat back to heat, the furnace kicks on and heat is coming out of the vents. All good.

But then we go to bed, and I'm woken up because it's freezing inside. I go to the thermostat. It says it's 55 degrees inside the trailer. When I take the up or down arrows it says it's set to 65. I repeat the process of turning off the thermostat and back on and things are working again.

Any ideas? Again I get heat so I don't think it's a propane issue. I've turned on the stove to try to flush out any air in the lines. But we've been out about 4-5 times and this has been an issue. Also I've never run out of propane. Filled it up with half bottles still. I believe one night it managed to keep the heating going. But all other nights, it doesn't.

Any ideas? We are about to head out to the mountain this afternoon and it's going to be cold. Hoping there might be some quick fix ideas to get us through the weekend.

Thanks

Peter

[Trksr]

Were your bottles properly purged before they were filled?

How cold is it outside. Moisture left in the tanks could freeze the regulator, stopping the flow. By the time you reset the heater things would have thawed.

Just a guess.

[5picker]

Since this seems to happen overnight, you're going to somehow need to see if/when the thermostat calls for heat, if the furnace tries to light or if the furnace simply does nothing.

If it is a digital thermostat, have you tried reinitializing it?

To me this sounds like a control board issue.

[Nick Danger]

I've had the exact same thing happen a couple of times. My next step is to change out the thermostat. Not certain it will fix it but I have to start somewhere.

[Etep]

Originally Posted by Nick Danger

I've had the exact same thing happen a couple of times. My next step is to change out the thermostat. Not certain it will fix it but I have to start somewhere.

Thanks Nick. Let me know what you find out. I see that the thermostat is showing heat at the time (might be blinking) so ya I'm not sure.

My only guess right now is ya, thermostat, or some sort of blockage in the ducts or something causing the overheat sensor to trip. The latter I would have no idea how to fix and taking it to the dealership for warranty I assume would be a massive nightmare as the issue is so intermittent and takes hours to occur.

Very much looking forward to hearing the results of the thermostat replacement.

[ooo_double_A]

Hello. I purchased a Forest River in 2022. Since day 1 i've had this exact issue. I've brought it to the dealership 4 times to get this fixed and every time it's been something different to which the issue still persists.

Hoping (even though this post is over a year old) that there was a fix to this that i could forward to the dealership to look at.

Fun Note - Family member has a 2021 model and has the exact issue. Best friend has the exact same model as myself and has the exact same issue. It's scary how identical the issues are amongst all three of our trailers...

[DES-1]

Was this ever resolved?

[DES-1]

We experienced the same issue. Believe the culprit is the sail switch. It is an air flow sensitive switch. I managed to get my heat (temporarily) working by shutting thermostat off, turning back on, going outside and blocking the intake with my hand. After a second I uncovered, which forced a sudden rush of intake air activating the switch, the heat ignited and worked for multiple cycles.

[Nick Danger]

Let us know if replacing the "sail switch" makes it work right.

[DES-1]

I’ve confirmed it’s the sail switch and my workaround reliability starts the furnace. I hate to think what a dealer will charge to remove furnace and replace it, so will add it to my to-do list, read up and tackle it myself as time permits.

[NMWildcat]

First thing I would do is inspect intakes and exhaust closely (mainly for nests/bugs etc), and use compressed air to clean as much as you can.
Amazes me how many times this has "fixed things" for me.
Just a few weeks ago the sail switch on my tankless water heater was not acting reliable, which was puzzling as I had replaced it last season. Took off the exhaust guard and found enough of a wasp nest to alter air flow around the sail switch.
Check the easy stuff first

[DES-1]

Originally Posted by NMWildcat

First thing I would do is inspect intakes and exhaust closely (mainly for nests/bugs etc), and use compressed air to clean as much as you can.
Amazes me how many times this has "fixed things" for me.
Just a few weeks ago the sail switch on my tankless water heater was not acting reliable, which was puzzling as I had replaced it last season. Took off the exhaust guard and found enough of a wasp nest to alter air flow around the sail switch.
Check the easy stuff first

Some of the new trailers don't have good access to the furnace internal ducting. And, our trailer was built just a few months back and has not had the exposure to things that could clog it up.

The compressed air technique might do the job for others, but it'd have to be a goodly volume in order to not just lodge the dirt deeper in the unit..

[NMWildcat]

Originally Posted by DES-1

Some of the new trailers don't have good access to the furnace internal ducting. And, our trailer was built just a few months back and has not had the exposure to things that could clog it up.

The compressed air technique might do the job for others, but it'd have to be a goodly volume in order to not just lodge the dirt deeper in the unit..

Yup. Just have to be smarter than what you are playing with.

[Guspech750]

Just last week. I turned on the furnace and it was rocking like it should. One night it turned off. It was 46 inside. Started brainstorming. Went outside to my truck and I noticed my wife had placed a folding chair right up against the furnace exhaust and intake. Moved the chair and we magically had heat again. LOLzzzz

[aceinspp]

When these campers are built a lot of debris is left and never cleaned up. Could be some of this interfering the sail switch so a good blow out might help. Later RJD

[DES-1]

Originally Posted by DES-1

I’ve confirmed it’s the sail switch and my workaround reliability starts the furnace. I hate to think what a dealer will charge to remove furnace and replace it, so will add it to my to-do list, read up and tackle it myself as time permits.

So much for my confirmation! It's behavior went from intermittent to non-functional. I've replaced the igniter board with a Dinosaur brand, and seems to run reliably now. Will do a few more tests and then consider it solved. Removal and reinstall of furnace was a bear...

[GolfingDave]

Had the same problem in my camper. Tried a new thermostat and still happened. Would come on if manually selected heat off then on.

Someone here turned on their water heater to gas instead of electric and problem went away. So I tried that for a day and have not had a problem since.

Makes no sense to me except that they are in the same area. That was last fall and camped all winter using both the propane and fireplace.

Just throwing it out there.

[ppine]

Thank you. Same problem in a Rockwood.
Just came back from a fall trip with below freezing temps. Now that I have Li batteries I can run the furnace in the morning. I never try to heat the trailer all night and just rely on a good down sleeping bag and some blankets.

[DES-1]

Originally Posted by GolfingDave

Someone here turned on their water heater to gas instead of electric and problem went away. So I tried that for a day and have not had a problem since.

That's excellent advice - turning on the gas HW heater 'proves out' the gas tank level, regulator, and most of the plumbing to the furnace. Process of elimination! I myself took a slight detour before thinking thru and trying the HW.

[bubbles]

Originally Posted by DES-1

We experienced the same issue. Believe the culprit is the sail switch. It is an air flow sensitive switch. I managed to get my heat (temporarily) working by shutting thermostat off, turning back on, going outside and blocking the intake with my hand. After a second I uncovered, which forced a sudden rush of intake air activating the switch, the heat ignited and worked for multiple cycles.

Maybe I'm wrong but that intake and the exhaust ports are for the combustion chamber which is isolated from the furnace output side to the RV where I think the sail switch is located and operated by the output side to the RV via the
squirrel cage fan.