Suburban RV furnace won't light, blows cold. Troubleshooting tips from RV TECH TIPS

how to diagnose a furnace that runs for 30 seconds and shuts off. Backdrop of the Nehalem River.

[AndiA]

You saved me 700$ on a new furnace I’m a 27 yr old chick with no prior knowledge were living in a fifth wheel and our suburban furnace went out and your other video showed me how to remove it and to diagnose the problem and I found out it was the circuit board I ordered a new one 100$ and my furnace is kicking through the NorCal snow right now thank god. Your videos are very helpful thank you so much my dude

[_apey]

Awesome! Fixed the 1996 25SF Suburban today. Replaced both limit and sail switch because both tested as intermittent.. There was a lot of Northern Nevada desert (playa) dust throughout the entire heater, including that sail switch. That stuff is like fine flour for those that aren't familiar. It's cleaned up pretty good now though. Thanks for the tip about connecting the two blue thermostat wires for bench testing. It's going to get down to 17 degrees here in TX in a couple of days. Appreciative to have found this video just in time! 🙂

[adamschmidgall]

Thanks for posting. Heat went out in the middle of the night. After trying to figure it out on my own, I watched your video. Didn’t have a volt meter but disconnected and reconnected the limit switch and it fired up. I’ll be buying a limit switch in the morning. Great video!

[JuanMartinez-egxd]

I appreciate the video it helped me with my heater, fixed it in about 30 minutes after so many cold freezing nights i got heat

[nmartin]

Another super helpful video! I have a 2006 model. Keep doing them!!! My LP in line is up front, looking through the outside access on the Motorhome.

[MMOverlandAdventures]

Excellent Chuck, Thank you!
Just replace my SF35Q with a RP35 in Dec '23. The SF started making lots of noise, bad motor bearing.
3 months later the RP came on, went off, came on went off blowing cold when on. Checked voltage at the high limit, got about 2.58v. Replaced that and the sail switch cause it didn't register 12v either on the neg side. Working now!

[matsulli]

Wish you could have shown the details on pulling the sail switch. Good video.

[TerryManess-kp]

Replaced sail switch, limit switch, and circuit board. Have the power to the switches like you showed but I get no clicking from the igniter at all. Have great power as I ma plugged into the house, propane tank is full and made sure I had gas to the heater. I have a Suburban SF-30F. What would be my next move?

[Shane_Little]

I'd love to see what you used to provide power to the furnace. Just alligator clips off a 12v battery? I did furnace stuff in school but it's been almost a year now, trying to refresh my memory. Great video, thank you! I actually have a Suburban furnace job this morning. lol

[tylernord]

Great video, I have no power to either side of the sail switch I haven’t pulled the unit to test the limit switch!

[stevesellers]

On my Suburban I had the same problem.... I would add to your 3, the regulator. I replaced the sail switch, limit switch, motherboard, ignighter, then finally fixed it with a new regulator (basically giving myself an almost new furnace). Check the flame on your stove (strength/color) to diagnose.

[Brian-]

Thanks for sharing i have same problem. Im fixing to tackle

[jackantoine]

Nice video, well done. If the unit starts and you feel a moment of heat and then the heater shuts down what would you look at.
Thanks in advance

[jamesmnoblesjr]

That was my problem. Thx, no more cold feet:))))

[adamhenderson]

Having this issue and great video! I'm not getting voltage to my sail switch and obviously there's no voltage leaving so I would assume the chip is bad not sending voltage to the sail switch?

[justintracy]

What is it if it lights for a split second then the blower keeps going but no heat and you can hear the igniter keep trying to ignite !!?

[n.g.]

Thank you for the video. Maybe I've missed it, but how are you able to test/know that unit is working properly after swapping sail-switch without having the gas-line connected to the unit? Or, do you not need gas in order to find out if it's working?

[WillBelden]

Good video, would've loved to see how to remove it, too! (I have a 2018 model, I guess, where the sail switch isn't so readily accessible.)

[georgechamberlain]

Stumbled on your site and glad I did
It’s great that you just jump right in and get at repair instead of lengthy preamble on other sites!!!
So here’s my problem I have done all the tests and replaced the burner head as it was rotted out
My attwood 8535-111 Excalibur fires up like normal but when I put the outside cover back on it goes out (sorry mine is an external access type) I know it’s old 1999 but I’m in a bad way so can’t be just buying needless parts etc
Do you work on RV generators ??? Don’t see much anywhere!
Keep on doing what your doing
Thanks Bill in the San Juan Island

[annemariearanda]

Do you have a video on how to get to the furnace? I have a Sunlite 16bh and there isn’t a panel outside the RV.