Propane furnace not staying lit

Sjm9911

Super Active Member
May 31, 2018
11,730
Nj
I would check the rollout and or sail switch on furnace. If it lights and goes out one of those may be bad. But they may be working properly and you have restricted air flow in the system. You did pull the cover off the inside , sometimes there is a switch there to reset it. And some have a faint lite that flashes a code, this tells you what the problem is.
 

Taxus812

Active Member
Jun 1, 2010
236
Sounds like you are getting decent advise. Couple of things you can eliminate.

1) follow all the lines from the tank and look for kinks and leaks (using soapy water on each connection

2) less likely but try a different propane tank. The tank has a built in safety that restricts gas flow. Perhaps it is malfunctioning.

While both these are unlikely they are easily eliminated and would cause weird issues like you describe.
 
Last edited:

p

Super Active Member
Jun 9, 2014
754
Alberta
Hello! Thank you for your reply! I'm not sure, to be honest, and I questioned this myself a few posts up. I can feel air going in and coming out the rear ports, but I am also thinking this whole unit would benefit from a good cleanup. I am seriously considering trying to remove the whole unit for further cleaning and diagnosis. I managed to get the gas connection at the solenoid valve free tonight, after that I think it's just a few screws in the front, the rear vents, and some wiring that needs to be disconnected so I can pull the whole thing out. If/when I do that, I will make certain that all the vents and everything are free of debris. So at this point unless someone has a real "ah ha" idea for me, I think my next step is to pull the unit and really clean it up. I'm thinking this is a gas blockage, like a spider web in the line or burner orifice.

Just to reiterate, I really think everything is working as should. When I turn the thermostat up, the blower kicks in. I can see the sail switch immediately getting pushed closed, the blower runs for 20 seconds or so, then I hear a click that I think is the gas valve opening, followed by the tick, tick, tick of the ignitor (which I can see igniting). Sometimes, I get maybe 2 seconds of blue flame igniting before the flame goes out. At this time the ignitor is still going. The ignitor stops after a few seconds, and I can definitely hear an audible click that I think is the gas valve closing because the burner did not light. This sequence repeats for three times as expected, but still nothing. Except for the "nothing", this seems like everything is working as it should, right?

So as long as I'm hearing what I think I'm hearing, everything is working fine. It seems like a lack of gas to me.
On my furnace I knew the outside air intake vent was blocked when I was on the inside furnace vent cover and while starting the furnace, it seemed like an a lot of air was being sucked into the furnace vent from the inside. This seemed, "odd", since the air should be going into the trailer from the vent not the other way around.
 

PaThacker

Super Active Member
Feb 11, 2010
1,493
Poconos
If you can’t purge do to missing stove search for quick connect under pup. None there. Start at regulator on front and process of elimination. Over 20 years old
 

Kdague

Member
Sep 15, 2020
49
So my thought is this. I’ve worked on trailer style furnaces. I pulled up a diagram of that furnace. And sometimes, tiny little spiders like to make webs in those tiny little holes that the gas pushes out of. Usually it’s at the gas valve itself. Yes u have to take it apart. Nothing should be reverse threaded. It should all be normal. Start by taking out the spark igniter and clean the probe with some sand cloth or a green scratchy. Then remove the tiny orfices that the gas blows out of and would have flame coming off of them. Clean them all really well with a small piece of wire. Then go Al the way to the gas valve and do the same thing. If u had could test the propane gas pressure at the gas valve it should be close to 10” WC. I’m guessing u can’t. Just try cleaning all the little orfices and getting a different tank and if that doesn’t work it’s either a plugged gas line, bad gas valve on the furnace, or a bad gas regulator down the line. If it lights and the flame gets blown out then u have a cracked heat exchanger or air leaking into the combustion chamber from the blower fan.
 

tfischer

A bad day camping beats a good day at the office
There are just too many variables here IMHO and we need to figure out if you have a fuel delivery problem or a furnace problem. Maybe you can find someone local with a stove that you can borrow long enough to test the gas flow at the quick connect?
 

ADK_ Adventures

Active Member
Apr 17, 2021
124
Hi guys! Thank you so much for your replies and suggestions! I got a chance to dive back into it today, and here's what I figure out now.

My furnace is just fine, my camper is not.

I have a gas feed issue on the camper side of things. I decided I wanted to pull the whole unit out and shake out the cobwebs and debris as best I could. I had been avoiding removing the furnace, but this turned out to be easier than I thought. I found a bee's nest blocking about 50-60% of the air intake, so I cleaned that out too. I connected the furnace directly to my gas regulator coming from my LP tank, and I connected the electric directly to the 12v camper battery. I shorted the wires for the thermostat, and it lit right up first try! Nice blue flame, just what you'd expect, and it started blowing warm air almost immediately. I disconnected the thermostat wires, and the gas valve shut off right away while the blower kept going as expected. I did this at least three times and it worked each and every time on the fist light just like it should. Nice!

Also, when I removed the unit I found a sticker on the back of the heater clearly stating this is a 2017 unit in my 2001 camper. This was a pleasant surprise, and explains when the heater always looked so clean like it hadn't been used much. We knew the previous owner changed the canvas, but they didn't mention replacing the heater.

Anyway, the heater worked great on it's own, and at this point I thought the reduction of intake air was the problem. I reinstalled the furnace in the camper, gave it another shot, and nothing. I mean nothing at all. Doing some digging I realized the I've now lost 12v coming to the furnace from the camper. I'm guessing I accidentally worked something loose somewhere when I was monkeying around with the furnace. Great. I'll figure that out though, that's just electrical.

So I brought the camper battery inside the camper and wired the furnace directly to the battery. This time it kicked up as expected, but I got the same result I had been seeing before; a brief blue flame that lasts a second or two.

So next I brought the whole LP tank in the camper, I hooked it up directly to the furnace with the 12v battery still hooked directly to the furnace, and Vwoosh! Kicked right on and ran just like it should.

So my problem is clearly on the camper side. I need to figure out what I did to the 12v, and I need to figure out if I have a blockage or something in the gas lines or fittings on the camper. Does anyone know how I go about diagnosing this problem?

Thank you all for your help, I really appreciate it!

-Amos
 

ADK_ Adventures

Active Member
Apr 17, 2021
124
yes.

Not the same model but this guy shows electrode alignment - second half suggesting your issue


I just wanted to say that I have watched at least 15 of this guy's videos in the last two weeks (some of the multiple times) and he is absolutely awesome! Easily the best YouTube "how to repair RV's and campers" channel that I've found. Darren is the man in the videos, he runs a profession, mobile RV camper repair service in Washington state called My RV Works. This guy absolutely knows his stuff, and his videos are very thorough and really easy to understand and follow. He was a huge help to me figuring out this furnace and my fridge situation too. I definitely recommend his videos for anyone doing these kinds of repairs. I have zero affiliation, and I'm in the North East US, but I really feel that strongly about his videos vs many others I watched recently. Just my $0.02.

Thanks @rabird !

And thanks, Darren, if you see this lol!

-Amos
 

ADK_ Adventures

Active Member
Apr 17, 2021
124
OK, further progress, but I am still frustrated and ready to give it a break for a while lol!

I decided to try to look at the gas fittings and lines on the camper. Not much to them at all. I started with the very first fitting on the front frame of the camper that the LP tank line connects to. I opened this fitting just for the heck of it, and out came a little piece of who knows what. I blew it out, and more crap fell out. I tried the furnace in the camper connected through the camper gas lines and wouldn't you know the darn thing lit right up. I can't believe it, and probably should have looked there sooner, but I think this clogged gas fitting has been my problem all along.

The furnace is now working in place, except I still don't have 12v DC at the furnace, I have to direct connect the camper battery to the furnace. I seriously don't know what happened. The 12v was fine all along, I never had a problem with the thermostat, blower, ignitor, etc. As of today, I'm not getting 12v on the leads coming into the furnace from the camper, and I cannot figure out why. Nothing looks loose or out of place. I checked all the fuses I know of (one at the batter and four on the power converter) and they look fine. The camper interior lights and porch light are working. Is there a fuse or something else I don't know about? Is there a wiring diagram for these campers somewhere? I do have the sink raised and that switch underneith should be closed. Anything else?

Thanks again, I appreciate the help!

-Amos
 

ADK_ Adventures

Active Member
Apr 17, 2021
124
Success!!!!

My 12v issue turned out to be a fuse at the converter box after all. Although the fuse looked good, I changed it with a new one and immediately got my 12v back. That was frustrating though. I checked because I have heard that fuses can look good but still be faulty, and indeed mine was.

I think my whole problem is solved, the heater seems to be working great. I’m in the camper now, it has to be 85 degrees outside, I’m running the heater, and couldn’t be happier lol!

Thank you all very much for tagging along and for your suggestions and help. I really appreciate it!!

-Amos
 

Taxus812

Active Member
Jun 1, 2010
236
How about you disconnect
Hi guys! Thank you so much for your replies and suggestions! I got a chance to dive back into it today, and here's what I figure out now.

My furnace is just fine, my camper is not.

I have a gas feed issue on the camper side of things. I decided I wanted to pull the whole unit out and shake out the cobwebs and debris as best I could. I had been avoiding removing the furnace, but this turned out to be easier than I thought. I found a bee's nest blocking about 50-60% of the air intake, so I cleaned that out too. I connected the furnace directly to my gas regulator coming from my LP tank, and I connected the electric directly to the 12v camper battery. I shorted the wires for the thermostat, and it lit right up first try! Nice blue flame, just what you'd expect, and it started blowing warm air almost immediately. I disconnected the thermostat wires, and the gas valve shut off right away while the blower kept going as expected. I did this at least three times and it worked each and every time on the fist light just like it should. Nice!

Also, when I removed the unit I found a sticker on the back of the heater clearly stating this is a 2017 unit in my 2001 camper. This was a pleasant surprise, and explains when the heater always looked so clean like it hadn't been used much. We knew the previous owner changed the canvas, but they didn't mention replacing the heater.

Anyway, the heater worked great on it's own, and at this point I thought the reduction of intake air was the problem. I reinstalled the furnace in the camper, gave it another shot, and nothing. I mean nothing at all. Doing some digging I realized the I've now lost 12v coming to the furnace from the camper. I'm guessing I accidentally worked something loose somewhere when I was monkeying around with the furnace. Great. I'll figure that out though, that's just electrical.

So I brought the camper battery inside the camper and wired the furnace directly to the battery. This time it kicked up as expected, but I got the same result I had been seeing before; a brief blue flame that lasts a second or two.

So next I brought the whole LP tank in the camper, I hooked it up directly to the furnace with the 12v battery still hooked directly to the furnace, and Vwoosh! Kicked right on and ran just like it should.

So my problem is clearly on the camper side. I need to figure out what I did to the 12v, and I need to figure out if I have a blockage or something in the gas lines or fittings on the camper. Does anyone know how I go about diagnosing this problem?

Thank you all for your help, I really appreciate it!

-Amos
I wonder if you disconnect the line from the furnace and reg and blow the lines out with air ? also look for hidden shutoff. Perhaps they added one when they installed the new furnace.

UPDATE: I seen your update after posting.
 

ADK_ Adventures

Active Member
Apr 17, 2021
124
How about you disconnect

I wonder if you disconnect the line from the furnace and reg and blow the lines out with air ? also look for hidden shutoff. Perhaps they added one when they installed the new furnace.

UPDATE: I seen your update after posting.
Hi! Thanks for the suggestion. Yes, my problem seems to be solved, but I’m sure the whole system including the fridge really needs to be cleaned and maintained to be at their best. I had thought, if there’s dirt or debris right at that first gas connector, then maybe more worked its way through the gas lines. I wonder if it’s possible to disconnect the gas, open the very first and very last fittings on the line, and blow air through the whole thing. Might be worth it.

Thanks again!

-Amos
 

Michael J

Active Member
Aug 9, 2018
117
If your gas problem comes back I'd check the regulator out more we bought a camper and you could tell the tanks had been off a while and the darn bugs had built nests in the end that goes onto the tank and the seller was nice enough to put 2 new tanks of gas on before selling us the camper and all that stuff went into the regulator and destroyed it in about a year, ya we didn't use much gas other than cooking so didn't notice it as we were getting enough gas though to achieve that but when we did start camping in colder weather it showed up really quickly on really cold night of about 30 degree outside furnace lit and ran good all the way till we went to sleep...... LoL
 




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