Furnace Problem

[thezoltar]

I just had the sail switch fail on my 2019 FC25FB. Turned out a squirt of WD40 into the switch made it good as new. Still using the old switch although we now own a spare. Amazing how much pet fur can accumulate around that switch!

[SSquared]

There are many different models of sail switch, depending on the brand and model of furnace. Of the ones I have seen, the "switch" part is usually the same, the difference is in the length and width of the metal flap (the "sail"). That said, when my wife and I replaced the sail switch on our friends' trailer last summer, the correct sail switch was discontinued and no longer available. We bought one that looked kinda similar and it worked fine.

On your model furnace, I don't know if you have to pull the furnace out to get at the switch, or if there is some way to open it up in place.

[GCinSC2]

Atwood AFM series service and parts manual.

https://pantherrvproducts.com/conten...Atwood-AFM.PDF

My furnace is the 8535 series, sail switch is on back side, I THINK this might be the newer AFS,M,L series with it on the front.

Darren at My RV Works has an extensive video series for lots of RV repairs and his site also has lots of service manuals.

Just noticed this is same as Azflycaster already posted. Good stuff.

https://www.youtube.com/watch?v=-g3_Y7MqChE

[eubank]

Kind of confusing because they show two different sail switches for this unit. See the last page in the PDF. (Note that they refer to them with the term paddle rather than sail. Just goes to show that nomenclature is not set in stone.)

Lynn

Originally Posted by LAWBC

Try this https://manuals.heartlandowners.org/...wood%20AFM.PDF

[PSU1981]

Thanks so much!!!

Glenn

[PSU1981]

Thanks for your help!!!

Glenn

[trilink5]

I ordered a new one. just cleaned the fuzziness off the existing one and that did the trick. I now have a spare.

[katieP]

Originally Posted by PSU1981

Looking for the model # for sail switch for Atwood AFM Series Furnace for 2015 27FB FC. The part diagram that came with the AS is unreadable.

Thanks,

Glenn

Hi Glenn,

Here is the Sail Switch I ordered from Amazon that I used to fix my furnace in my 2018 Globetrotter. I had it into the dealer 3 times and they couldn’t fix it. The blower would go for a few seconds and then not light. As soon as I switched out the sail switch with bracket, it worked perfectly.

Dometic 33082 Svc Df Sail Sw W/Brkt M/L Kit https://www.amazon.com/dp/B08CFZX48F/ref=cm_sw_r_sms_api_glt_fabc_FA8CX6NZK4J7C7ATS5D7? _encoding=UTF8&psc=1

[JohnTF]

Vary common that bugs get in there & build nest , then does not operate .
Cleaning then works .
I put a stainless screen under the outside holder to keep the bugs out .
Another airstream lack of - good engineering .

[carl2591]

actually atwood lack of good engineering.. they could have put a nice SS screen in the exhaust or designed the nozzle cover with it. AS just buys them from Atwood..

Originally Posted by JohnTF

Vary common that bugs get in there & build nest , then does not operate .
Cleaning then works .
I put a stainless screen under the outside holder to keep the bugs out .
Another airstream lack of - good engineering .

[JohnTF]

Originally Posted by carl2591

actually atwood lack of good engineering.. they could have put a nice SS screen in the exhaust or designed the nozzle cover with it. AS just buys them from Atwood..

So Airstream had no choice in what they put in their trailers ?
Or how they installed it ?

[eubank]

There aren't that many manufacuturers of RV appliances, including gas furnaces. Suburban and Atwood (Dometic) are the most common ones, I think. Each one comes with mounting instructions for safe operation, pretty much like household appliances to.

Lynn

Originally Posted by JohnTF

So Airstream had no choice in what they put in their trailers ?
Or how they installed it ?

[David in Lex]

When we replaced the furnace’s sail switch on our 2020 FC 30 RBQ, we figured out the model number of the furnace and goggled it. The Atwood website told us what switch to order. Before placing the order, I called Atwood just to be sure. Easy to replace the old one with the new.

[dan20]

I have a 2021. 19 ft Bambi. The furnace failed. Blower would come on but not ignite.
Took it to a RV dealer in Colorado, not AS. They told me it needed a new furnace and quoted a price of 600.00 plus labor about 175.00.I declined and towed it home and called Dometic. Spoke to a very nice lady and told her my experience. She was aghast that a Dometic authorized service dealer would suggest such a plan. She sent me a new sail switch free which I received in 48 hours, installed it myself. Problem solved...

Dan

[CBWELL]

Don't you just love the "honest" RV dealers!! You have learn how to do repairs yourself.

[PSU1981]

My furnace model # is AFMD25141

Sail Switch#31094

Replaced today & furnace fired right up!!!!!! Yeah!!!!!!!!!

Thanks!!!!!

Glenn

[PSU1981]

Replaced the sail switch today & it fired right up!!!!

Thanks for all of the help!!!!!!!!!!!

Glenn

[umasslax]

Furnace steps

1. The Thermostat calls for heat, sending DC current to the furnace.
2. A Time Delay Relay is energized and passes battery DC power to the blower motor.
3. The blower motor and fans spin, pulling air from the Air Return and generating a stream
of air through the Heat Exchanger and out the Ducts. At the same time another fan pulls
air from the Combustion Air Intake into the Combustion Chamber and out the Exhaust.
4. The fan air stream causes the Sail switch to close as the blower gets near full speed.
5. Power flows to the High Limit Switch and onward to the Control Circuit Board.
6. The Control Circuit Board opens the gas valve and generates a spark at the DSI Igniter.
7. The Burner ignites, building heat in the Combustion Chamber.
8. Heat passes through the Heat Exchanger, warming the air circulating through the Ducts.
9. The Thermostat reaches the Set Temperature and opens.
10. Power is removed from the Control Board and the Burner shuts down.
11. The fan continues to run to cool the furnace, until the Time Delay Relay

[Bucky G]

Originally Posted by azflycaster

The blinking led is the error code. It will blink 1, 2 or 3 times and then repeat over and over. 1 blink is air flow (sail switch) error. The sail switch tells the circuit board that the fan is running and signals the gas valve to open.

Here is a good video...

This was spot on for our 2021 27FB Globertrotter. No heat, fan running, check a few things and found this string.

Watched video went and pulled my furnace cover,Four screws,pooped right off(Be carefull screwing back on,make sure screws realign ) reset switch and flapper switch both easy access. Clean hair and dust from flapper and away we went.
Thank you all those that post helpful videos or other helpful hints.

[Bucky G]

Great videos!