Replacement sail switch issue.

[LittleSkippy]

Issue: With the sail blade set at factory bend the furnace does work, BUT on startup and shutdown the switch blade contacts the fan blades and it sounds like a roulette wheel until the air pushes the switch blade out of the way. Like 3 seconds start up and 7 seconds on shutdown.

1) Metal to metal contact can only lead to bad things.
2) It is noisy, so it will be disturbing while sleeping.

Sail switch part number 31094.
Atwood hydro flame model AFMD25141 in our 2017 Airstream.

Ordered new sail switch from our local Airstream dealer – part number 31094. The is the part number that they show for our model, and the one listed in our manual. This sail switch is the skinny one that mounts on the from of the fan. It was a two pack and both switches acted the same.

Installation and testing.

OK, so got the new sail switch and installed it. I noticed when I turned the fan, by hand, the metal tip of the switch contacted the fan. The fan would turn, but made clicking noises. So, I took the switch out, bent the metal blade back, just a tiny bit, and it stopped hitting the fan. Test fired the furnace and the gas would not light, furnace timed out.

OK, let’s bend the switch blade back to original shape. The switch blade once again contracted the fan blades lightly, and the clicking noise is back. Tested the furnace and it light and worked fine as normal operation.

Any idea how to fix / get around this issue?

[Steamy1]

We just installed a new sail switch for this season, and on our first night staying in a state park, the furnace would not light. I removed the switch and it looked fine. I turned on the furnace withe the sail switch removed but connected, then manually pushed the blade, and the igniter was activated. It just would not work when installed.
Found a replacement at a trailer supply/dealer and it worked perfectly and continues to work.

I think the takeaway is that these switches are not made to precise engineering standards.

Side note, when I was trying to locate the switch (31094MC) I called Atwood support, and they told me it was a discounted item and no longer available. Their suggestion was that I purchase a new furnace.

My suggestion is to try replacing it again. You may just had bad luck in receiving sails that work.

[TitusNW]

Might try just bending the top edge to clear your fan wheel and leave all else as original.
Steve

[LittleSkippy]

Thanks to all.
I have tried bending the tip of the switch blade.
Na, same thing.
I did try going back to the switch I thought had failed.
Bent that so it lightly touched the fan blades and it works.
Hmmm. No wonder our Airstream deal says these switches are the number one parts item they sell.

Once I figure this out, I'll post what eventually works.
Thanks, David

[JJTX]

Originally Posted by LittleSkippy

Thanks to all.
I have tried bending the tip of the switch blade.
Na, same thing.
I did try going back to the switch I thought had failed.
Bent that so it lightly touched the fan blades and it works.
Hmmm. No wonder our Airstream deal says these switches are the number one parts item they sell.

Once I figure this out, I'll post what eventually works.
Thanks, David

My 2024 furnace switch failed in less than a year. But it was not due to its contact with the fan, it was just defective. I replaced it and its working now. I will say they insert a very specific way and the blade on mine was NOT bent near the end, it was straight.

I would say make sure its the right one. They are not all the same. Theres even a new part number from previous generations. I have a thread in here on the subject as well.

I would try the bending method if the switch works othewise. It should not be contacting the fan. The fans rotation pushes the switch blade back.

I wont be surprised if more users don't jumper and bypass this switch. It seems to be an entirely cheap and unreliable way to determine the fan is spinning .

[Steamy1]

I wont be surprised if more users don't jumper and bypass this switch. It seems to be an entirely cheap and unreliable way to determine the fan is spinning .[/QUOTE]

I wonder if an aftermarket supplier like Dinosaur Boards could design the capability into the board itself?

[damonbeals]

If the sail is different on the new switch, just swap them, remove it from the old switch and put it on the new one. I had to do that with the sail switch I bought on Amazon.


Damon
#4827

[Bob Thomson]

I had a metal on metal sound with the furnace fan and the problem was unrelated to the sail switch. The clamp holding the fan cage on it's shaft had failed and the fan was sliding on the shaft and contacting something. I replaced the clamp with a tiny hose clamp. Since then I have heard that a tightly secured small wire tie will also work.

[kenfconnor]

2018 FC. Here is what I use. DTAIR 33082 Sail Switch... https://www.amazon.com/dp/B09XJV7P9X...p_mob_ap_share

[Dr. Ohat]

Hey all,
Not having a problem yet, but want to get a spare and be prepared to swap it out when I do. Anyone got any threads on replacing a sail switch on a 2021 Flying Cloud Atwood AFMD30? Never done any maintenance on the furnace but most other systems.
Thx,
Greg

[mythbuster88]

Originally Posted by LittleSkippy

Thanks to all.
I have tried bending the tip of the switch blade.
Na, same thing.
I did try going back to the switch I thought had failed.
Bent that so it lightly touched the fan blades and it works.
Hmmm. No wonder our Airstream deal says these switches are the number one parts item they sell.

Once I figure this out, I'll post what eventually works.
Thanks, David

We are waiting to see what happened here.

In my case I fiddled with it until it worked.

[LittleSkippy]

OK, the saga continues.
For the same part number there seems to be two different sail switches. One is White in color and has a thinner and longer metal sail. The other is Black in color. Both Amazon and eBay have them. Check your part numbers.

The one that I had trouble with and thus started the thread was a new one from Airstream, a Black switch.

So, what I did was go back to the White colored switch (installed by Airstream in the fall 2024) that worked for our 4 month winter trip. That one got intermittent. I had to submit the manual work around for the last week.

Anyway, I took that old White switch, when I could not get the new Black one working and bent the metal sail to match the newer black one and bent it a little further down until it gently contacted the fan - the furnace did light now.

Just back from a two night birthday trip and that older White switch worked 100% fine. The noise stopped.

OK, maybe the suggestions of something getting stuck on the fan may be the problem, or at least contributing to it. Maybe it worked it's way out of the system. I still need to get in there with a mirror and light and really look.

Thank all you for your help in solving this issue.
If I had to make suggestions I would.
1) Remove the switch and check to see if the fan has anything on it. BTW, when I did look at the switch after it failed I did not see any hair, or debris.
2) Buy the White switch, OR buy the one recommended by the post in the thread. It looks like a black one, but if one of you recommends that it works, then that is a good starting place.
3) Know the manual way to bypass the sail switch. Not the safest method, but like me if you boondocking in freezing weather, then you do what you got to do man.

The furnace is really great, and allowed us to winter boondock.

Thanks again everyone !!

[JJTX]

I would bypass this in an emergency without any hesitation. Mine actually started to go bad when the temps went down into the 20s. It was a COLD couple of days! Fortunately it was not that cold, that long.

It simply ensures the fan is moving with enough RPM to push the switch closed. You can jumper this with a paperclip.

The heat pump does work decent on these campers, however it will have ZERO heat on the floor or holding tanks, and you can get freezing water pipes. BAD!

Plus, holy jeezes the floors get cold without the LP heater!!