Propane Furnace won't ignite

**OwenTrail** · 10-09-2023, 05:14 PM

I have a older 1996 TM with a Suburban Gas Furnace. Was working fine the last time I used it this spring, but when I went to use it a week ago this fall, it would not ignite.
The thermostat is working a-okay, it will kick the fan on and then can here the igniter try to light the gas, but with no luck. Any direction on where to track down the problem will be appreciated.
All other gas appliances work, Stove and water heater.
The unit is a Suburban furnace, model #NT-16SE

Thanks - OwenTrail

**jagizzi** · 10-10-2023, 09:26 AM

I have the service manual for the furnace with a troubleshooting section in it. Give me your email address and I can send it over. I don't know how to attach a file here.

**jagizzi** · 10-10-2023, 12:17 PM

Got it figured out. Here is the Suburban Furnace Service Document. FWIW I replaced my furnace this summer and it was very straightforward. Disconnect the propane line and electric and then slide the unit out into the TM. The shell stays in place. You'll have to do this anyway to replace components I would think. Good luck!

**OwenTrail** · 10-10-2023, 05:35 PM

Jim and Kelli, thank you so much. This should do the trick. Happy Trails

**Kidkraz** · 10-12-2023, 09:53 PM

I had my camper out and found my heater wasn't working either. Your posting was perfect timing for me. Love this forum and all the great people on it.
Thank you for posting the manual.

Shane826 · 10-13-2023, 07:02 AM

Kidkraz & OwenTrail- Please be sure to post here when you figure out the problem! This forum only continues to grow when people share their solution and how they got to that solution.

Wavery · 10-13-2023, 10:10 AM

It's most likely an air flow issue. The furnace has a "Sail switch" in the air intake and the exhaust outlet. If there is any airflow disturbance when the fan kicks off, the gas valve will shut off immediately.

It could be spider webs, mud dobber nests or a host of other obstructions. Those furnaces are pretty indestructible and very serviceable. They seldom need replacing.

Having said all that, we never use ours. They are so noisy and they put out so mush heat that they fire-up, warm the space quickly causing the thermostat to turn it off. 5-minutes later, the camper has cooled down and the thermostat turns it back on (about the time that we fall asleep). so it goes all night long.

We bought a Mr Buddy heater. It's silent and does an amazing job of heating the camper. We've used ours in +15* temps.

Shane826 · 10-13-2023, 11:15 AM

Agreed on the use & noise but I think the sail switch is working correctly because it’s calling for ignition. I’m guessing a gas blockage.

**Kidkraz** · 10-13-2023, 12:12 PM

Unlike Owentrail, I'm not sure I have power to the furnace. The only sounds was from the mechanical switch at the thermostat. Water heater and stove both worked with the gas. I'll definitely post what I find. I thank Waverly on reminding me to check for blockages, cause the camper sat for 2 year before this year and it's only been used two different trips. I've seen & found way too many spiders for my liking.
Not sure when I'll be checking it out, but will give info on whatever I find.

Shane826 · 10-13-2023, 01:10 PM

Sorry I forgot there were two separate furnaces being discussed!

Kidkraz- Even if the thermostat clicks it can still be bad, especially if it’s the original mechanical tstat. Disconnect the two wires at the tstat and twist them together. Does the furnace start and run? Bad thermostat. I’d replace it with a simple non-programmable heat-only tstat.

https://a.co/d/34UF2FB

https://a.co/d/08U2bWz