Sail Switch Fun

[bborzell]

It has been interesting to follow the numerous threads about Atwood/Dometic furnaces refusing to fire because of uncooperative sail switches.

For the most part, I have been fine watching from the sidelines. After all, we don’t travel with pets and we are pretty good about dusting and vacuuming the interior of the camper. And, since we have done a ton of camping and traveling cross country twice since we picked up our 21C on the first possible day after the Great Flood of 2021, I figured that any sort of physical complication such as the sail hitting something inside the fan that it shouldn’t touch after nearly a year was unlikely.

So, this morning I went out and checked the interior temp and realized that it was sitting at 34 rather than the 42 I had the thermostat set at. I decided to open up the outside furnace cover and see what was what. There was a flashing red LED that indicated an air flow issue.

I called Dometic and was told that, since the furnace was still within the warranty period, I could take it to an official Dometic service center and, if any parts were found to have failed, as in defective, Dometic would pay parts and labor.

Since getting on that train for a $20 part seemed excessive, I asked for the sail switch part number for my furnace. The rep asked for the model number of the furnace and then came back with a SW part number.

Problem with that was that the part number she gave me was for a switch that had been split between two serial number ranges; one number for the early range and another for later builds. Only, neither of the parts carried the number she gave me.

So, I decided to remove the switch and, lo and behold, as I was working the sail out of the fan housing, I thought I saw mouse whiskers. Turned out that, despite not having pets, the tiny button that the sail is supposed to depress was fouled by a few strands of human hair.

Cleaned out and returned the hair strands to their rightful owner, reset the switch into the housing and, suddenly there was heat.

Still not clear on the actual part number for a spare switch, But I am guessing that the number I was given would be best ignored.

[YakRV]

I’ve had some sail switch “fun” lately too. Camped with early morning temps in the mid-30s (F). Went to bed with furnace running fine. Woke up around 5:00am with the inside temp in the low 50s and furnace giving signs of a tell-tale sail switch issue. Finished camping with a small portable heater (worked great, ac heat strip does as well).

Once home, I removed the sail switch and found a tiny piece of fuzz caught in it. Released the fuzz, reinstalled, and worked fine again……until our next trip. Started the night working okay, but it went out in the wee hours again.

I’m now planning to replace the sail switch (and get a spare or two). Model number I’m seeing for the sail switch is #33081 (for 2022 21C). Hope that’s the right one.

[diannelgraham]

Originally Posted by YakRV

I’ve had some sail switch “fun” lately too. Camped with early morning temps in the mid-30s (F). Went to bed with furnace running fine. Woke up around 5:00am with the inside temp in the low 50s and furnace giving signs of a tell-tale sail switch issue. Finished camping with a small portable heater (worked great, ac heat strip does as well).

Once home, I removed the sail switch and found a tiny piece of fuzz caught in it. Released the fuzz, reinstalled, and worked fine again……until our next trip. Started the night working okay, but it went out in the wee hours again.

I’m now planning to replace the sail switch (and get a spare or two). Model number I’m seeing for the sail switch is #33081 (for 2022 21C). Hope that’s the right one.

I thought that model was obsolete and the new model for the 2021 furnace was 33082

[Rossue]

Originally Posted by YakRV

I’ve had some sail switch “fun” lately too. Camped with early morning temps in the mid-30s (F). Went to bed with furnace running fine. Woke up around 5:00am with the inside temp in the low 50s and furnace giving signs of a tell-tale sail switch issue. Finished camping with a small portable heater (worked great, ac heat strip does as well).

Once home, I removed the sail switch and found a tiny piece of fuzz caught in it. Released the fuzz, reinstalled, and worked fine again……until our next trip. Started the night working okay, but it went out in the wee hours again.

I’m now planning to replace the sail switch (and get a spare or two). Model number I’m seeing for the sail switch is #33081 (for 2022 21C). Hope that’s the right one.

Why would you replace a switch when the fix was removing da Fuzz? If I have a problem I will use compressed air first as it is a PITA to replace in my 2014 trailer.

[YakRV]

Originally Posted by diannelgraham

I thought that model was obsolete and the new model for the 2021 furnace was 33082

I don’t know for sure. Just going by pictures of the sail switches that pop up on Google, the actual switch part of both the 33081 and 33082 look the same. The housing for the 33081 looks right to me. I could be wrong though.

Edit: From bborzell’s contact with Dometic, they sound confused too. That’s not good.

[Bcescapist]

We are currently camping in freezing temperatures in Arizona and our furnace isn’t working. We have both cleaned and replaced the sail switch . A lovely couple also with a 17 in Lees Ferry loaned us their spare circuit board to see if that was the problem but it didn’t help either. Only blows cold air and tries 3 times to ignite and then shuts off. We’ve purchased a propane heater but not nearly as effective or convenient. Not sure what to try next and would welcome any suggestions.

[Perry Butler]

Originally Posted by Rossue

Why would you replace a switch when the fix was removing da Fuzz? If I have a problem I will use compressed air first as it is a PITA to replace in my 2014 trailer.

In the first few months after we picked up our 5.0 in October 2018 I removed the switch and blew fuzz out four or five times. One morning was about 15 degrees.

Tired of removing the switch and blowing, a new switch was purchased/installed and the fuzz stopped catching. It’s been over three years and easily 400 nights with the furnace running great. We do carry two extra new switches, so we’ll probably never need them.

Last week I removed the loose flexible duct that was about 4” in effective diameter and installed a solid 5” duct, as well as removed the air deflector that also impedes airflow. Don’t know if this will help keep the fan blowing fast enough so the switch will engage, but it seems there is more hot air coming out of the furnace.

Originally Posted by Bcescapist

We are currently camping in freezing temperatures in Arizona and our furnace isn’t working. We have both cleaned and replaced the sail switch . A lovely couple also with a 17 in Lees Ferry loaned us their spare circuit board to see if that was the problem but it didn’t help either. Only blows cold air and tries 3 times to ignite and then shuts off. We’ve purchased a propane heater but not nearly as effective or convenient. Not sure what to try next and would welcome any suggestions.

Some had to replace their gas solenoid.

Food for thought,

Perry

[YakRV]

Originally Posted by Rossue

Why would you replace a switch when the fix was removing da Fuzz? If I have a problem I will use compressed air first as it is a PITA to replace in my 2014 trailer.

Ha! I guess in my attempt to keep a long story short I omitted a step. After the furnace failed the second time I removed the sail switch again, expecting to find another strand of fuzz. This time the sail switch was clean as a whistle. Now I think I’m just going to replace the darn thing since they seem to be so sketchy.

PS - I’m really glad the newer Escape models have the outside access panel. This sail switch stuff is annoying enough without having to tear out the furnace. Yikes!

[splitting_lanes]

Originally Posted by Perry Butler

In the first few months after we picked up our 5.0 in October 2018 I removed the switch and blew fuzz out four or five times. One morning was about 15 degrees.

Tired of removing the switch and blowing, a new switch was purchased/installed and the fuzz stopped catching. It’s been over three years and easily 400 nights with the furnace running great. We do carry two extra new switches, so we’ll probably never need them.

Last week I removed the loose flexible duct that was about 4” in effective diameter and installed a solid 5” duct, as well as removed the air deflector that also impedes airflow. Don’t know if this will help keep the fan blowing fast enough so the switch will engage, but it seems there is more hot air coming out of the furnace.

Ha! I had to remove and reinstall the sail switch a couple of times on our cross country trip. The last time it still wouldn’t work, so I bent the sail to put it into the airflow further, and that gets it to light reliably, but now when it shuts off and the fan spins down you can hear a tick-tick-tick of the sail hitting the fan.

I’ll try a new switch, and a solid duct. Great idea! If you have a part number for the switch you used, please post it.

[Perry Butler]

Originally Posted by splitting_lanes

I’ll try a new switch, and a solid duct. Great idea! If you have a part number for the switch you used, please post it.

The sail switch I installed was sent to us over three years ago by Dometic under warranty and the box is long gone. No idea what the part number is, but I’ve got a feeling it was bent differently to catch more air.

Enjoy,

Perry

[Eggscape]

Originally Posted by Bcescapist

We are currently camping in freezing temperatures in Arizona and our furnace isn’t working. We have both cleaned and replaced the sail switch . A lovely couple also with a 17 in Lees Ferry loaned us their spare circuit board to see if that was the problem but it didn’t help either. Only blows cold air and tries 3 times to ignite and then shuts off. We’ve purchased a propane heater but not nearly as effective or convenient. Not sure what to try next and would welcome any suggestions.

I trust you are plugged into power and your batteries are full charged. If not your batteries may be low enough that the fan will not spin fast as fast as it needs to push the switch.

[Bcescapist]

Thanks will look at gas solenoid as furnace won’t work on battery or shore power.