RV Furnace With An Intermittent Sail Switch -- My RV Works

[@marcelorescala8935]

This is the issue I had over the weekend. I suspected it was the sail switch, but when I tested it, after removing it, I could not find any problem. So I put everything back together and I started looking for the part # as I was pretty sure it was eventually going to fail again. As I search for the part, I notice that the manual that came with the RV/furnance was referencing part number 33063, however, that was not available on-line and everthing was pointing to 33081. Clearly has been engenieering change and that is the reason for the part number change. So your comment about Domestic knowing about that issue might be spot on, even when they will never disclose it publicly. Thanks for your videos, I've learned a ton. You have no idea how much you help people like me, that we are very handy, but we might lack some knowledge to complete the repairs. THANK YOU (also on behalf of my wife that was able to sleep well after I fixed the furnace!)

[@mikebrant192]

First, many many thanks. We've been diagnosing this exact model with this exact problem for months now. I have never even HEARD of a new switch being intermittent, and every time I tested it the sail switch was perfectly operational. This has been simply diabolical! Again, many thanks!

[@Robnord1]

This *was* very helpful. I have one of these newer units scheduled for next week, and being a lower volume service center, had not seen one of the new ones yet. 👍 You're a good teacher. Crisp, clear video and audio. If you ever do videos for pros, I would consider paying for them.

[@stevenpelayo9418]

Happened to us too. 2019 Melbourne Prestige. Found another video diagnosing this issue and recommended new sail switch. Swapped it out in 5 minutes and have not had any further issue for past two years.

[@hillbillyrv]

Dometic has a problem with their sail switches.....that's an understatement. Thanks for the video Darrin

[@joemelton7023]

Hello Sir, I wanna say Thank you . Your videos made it possible for me to fix my furnace problem. I couldn't get a service provider to show up. I don't believe I could have chased down and solve the problem with your videos. Thank you for education you provide.

[@walterrogers9801]

Good info ! I see a lot of posts on forums from rvrs describing these exact furnace symptoms. I will recommend them to your channel.

[@LordFalconsword]

We had this problem AND the manufacturer kinked the rubber propane line next to the propane tanks. After replacing the sail switch (bought two extras). I still had a low flame, flame out problem. That's when i found the kinked line, cut a zip tie, zero problems since (more than a eyar).

[@shane3878]

I've replaced about 5 of these sail switches since November on our 2021. The cheapos from Amazon last longer than the one we got from a RV repair guy. But they are all intermittent. They work better when they cycle frequently. I bought one from a RV place out west that is supposed to be the newest trouble free version but I haven't installed it yet. Some brackets need to be modified. Dometic had bad switches and bad brackets. I just keep reusing the same 2 brackets.

[@11Bretired]

Excellent video. This has really helped me. Thank you!

[@costarica0904]

Thank you!!! You always make Great Video's!

[@patrickstiltner1207]

Awesome video as always! Thank you!

[@jimlong527]

That will help thank you.

[@bobt6820]

As a newbie its a great help watching and learning from your videos ! I do have a similar problem...the furnace fan will run without stopping for 10-11 minutes before gas is ignited and then heat is blowing until thermostat reaches set temperature. Any advice? Thanks Bob T

[@lattermanstudio]

My sail switch used to dirty over time then one of the spade connectors was not making good contact over time …. This switch is prone to very simple solutions without extensive testing

[@captainmidnight7012]

Thanks great information.

[@johnr5545]

Thanks for the help god bless

[@dailylife3975]

I'm in Puyallup Washington and my furnace kicks on but won't fire

[@davidsizemore7613]

HELP... I have an Atwood Mod#8520-IV-DCLP SN# 1022370. The furnace comes on, blows, and ignites. Then after about 8-10 seconds, ignition stops and blower continues. No lights on the control board. I've watched 2 of your videos, and am still stumped. Any advice?

[@laundrymanadams6105]

Good video, question if the sail switch was the cause will the unit do an auto reset or do you have to turn the unit off to clear the fault. I have a friend that seems to have the intermittent problem but he said the unit will start without turning it off and back on. Thank you sir

[@chrismorgan89084]

Again another GREAT video from My RV Works - Darren! Your channel is fantastic and has helped me repair my 18 years ole Alfa from Atwood heater to Dometic refrigerator to plumbing issues etc. Without your knowledge base, I probably would have spent $$THOUSANDS$$$ at dealers in repairs. Thank You!

[@robertnasser9937]

Carry a new sail switch and a high level sensor (both about 30 bucks).

[@rachelhiers5260]

Having trouble with our furnace resetting on its own. Any advice? It runs good and hot, lights, and stays lit but for some reason something is making it trip to the off position. Doesn’t happen everyday or even every time it runs. I haven’t noticed a blinking light for the issue.

[@MyRVWorks]

If you can access the control board while the furnace is running, you would look for that white connector that is connected to the DSI board. Study the schematics for your furnace, usually there's a sticker on the furnace itself, but you're looking for voltage coming from the sail switch and high temperature switch - that circuit is on a daisy chain. It's possible your high temperature switch is faulting out. But the only way to prove that is to follow the trail on that circuit. So that would be where I would start.

[@rachelhiers5260]

@@MyRVWorks okay that helps. I did check the voltage on the parts and they seem okay but I could’ve done it wrong. I will say we did turn it on this am it ran for a little then shut off and it kinda smelled like something was possibly burning from the back of it inside? I don’t know if burning is the right word but just seems like temperature isn’t being regulated properly. Could it be the blower motor even tho the fan runs fine? There’s no sort of squealing or strange noises coming from it. Or would it definitely be the high limit switch since it’s tripping out due to over heating possibly?

[@ascension8811]

Where do you get your parts from and are they wholesaling the parts? Do you stock a lot of parts or do you order and then come back?

[@MyRVWorks]

We work with vendors and stock the most common parts for repairs. We try to get wholesale prices whenever we can.

[@alaskauntamed6476]

I’ve been following your furnace videos trying to diagnose mine, it clicks, turns on, hot air blows out the exhaust, but the heat blowing out the vents inside the camper is weak. Not to it’s fullest potential. Clogged gas valve ?

[@MyRVWorks]

Have you verified that all the Ducts are attached and not kinked or clogged? I have seen this when the duct has come loose from the furnace.

[@alaskauntamed6476]

@@MyRVWorks I pulled off the ducks and verified at the source that it is blowing weak

[@MyRVWorks]

Okay copy that. Your issue maybe the motor. If you can get an amp draw and compared to the motor nameplate. Another thing would be to verify you're getting 12 volts to the furnace.

[@pvf1799]

The furnace on my Jayco 28.5 RSTS is buried in the closet. No outside access panel. How do you bench test the sail switch?

[@FranksBmwAdv]

i have my sail switch out, is it spring loaded, mine just seems to flop around. I have the same intermittent issue. thx

[@henrymorgan3982]

Thanks for a great video. Very clear explanation of the problem. Thanks again!

[@gerardovera223]

On my rv it was back fire they told me that it was missing an orffice hofolly that will fit it

[@bobbieabbott]

My rv is new and my furnace has been acting up, I have found that at the thermostat I have to have the lever at a precise spot it can not be moved otherwise the furnace will not work. Then I can turn the thermostat to the on position and it will run. I can not turn the thermostat on then set it even if I put it in that exact place it will not run. If it does shut off and turning the thermostat on and of does not start the furnace, I will go outside and remove the panal and the red light will be blinking, once I reset it alot of time the furnace will start if not if I wiggle the wires which are clipped on to the sail switch it will come on. So is it my sail switch or a combination of issues going on? I want to find a rv tech who is in his 60's and lives in Florida who want to be my neighbor so I can have someone close by and build a relationship with.

[@charlesyoungblood7561]

Great Job!

[@marcuscarmouche9023]

Great video Darren I just finished a Dometic ceu class a couple weeks ago and they said they are now notching out the housing on the switch to resolve this issue on the new switches.

[@MyRVWorks]

Thanks for the tip!

[@marcuscarmouche9023]

@@MyRVWorks anytime bud glad to be able to give something back keep waiting to see if you post a unity board video or bmpro video to see if I can learn a new trick on one or the other.

[@egregg57]

I have had to fix more than a few of these. They were nothing like what I had expected at all. Anyway, quick fix after you know what to do! The switches can be very flaky!!

[@virtualdent]

Thank you Darren watching your videos helped me to diagnose and successfully replace a bad gas valve with my furnace "Happy campers say my RV works"

[@cpcoark]

Good job. My question is it the sail or the micro switch causing the problem. I have be seeing the micro switches failing.

[@love2drop289]

That has been our exact issue!! I have been searching the internet and you hit the nail on the head. Since Dometic has been having issues with these parts on new furnaces, are you finding the replacement parts are more stable?

[@laundrymanadams6105]

Ok good info but question, if the heater fails on sail switch does the unit do an auto reset or

[@redc8783]

May it very clear what and where to look 😎🥸