FURNACE ISSUE - Montana Owners Club

Larry-P · 10-11-2011, 04:08 AM

My coach is a 2011 model, just picked it up 1 month ago.
Furnace was working okay throughtout the night & this morning. Both tanks are full. As it has in the past.
The furnace is now going on but does not heat. After a short period it shuts off.
I've tried the stove & it works fine so I know I'm getting gas. As I'm sitting here at the computer typing this message the fan is running & I here a click of some type down below & the computer screen blinks. But no heat. Furnace then shuts off.
This same thing has happened in the past. Suddenly the furnace will start working fine.
Also, just tuning up the thermostat does not cause the furnace to go on.
Any suggestions ??

Larry-P · 10-11-2011, 04:17 AM

I again turned the thermostst up a couple degress & shut the control center off & on & now the furnace is working again. Giving off plenty of heat. This is driving me nuts.

nosticks · 10-11-2011, 06:45 AM

Two places with good troubleshooting issues.

http://www.ducktec.com/furnace-trouble-shooting.html
http://bryantrv.com/docs.html

Also, I had the same problem you describe. Dealer found loose wire on control board. They reattached it, so far so good, no new problems.

Art-n-Marge · 10-11-2011, 06:47 AM

Sounds like the thing that keeps the propane open when trying to fire up the furnace (the thermocouple?) but hang tight, Ozz should be on very shortly. He's a retired Furnace guy who's very good at this stuff. You might even try looking him up and sending a PM or email for a quicker response.

Ozz · 10-11-2011, 08:21 AM

Thanks Art, but I have never worked on the RV furnace, just connected to the circuit board with wires to run the furnace fan to circulate the air. I did comment earlier that the flame rod sounded like the culprit. Now, with further info Larry provided at 10:15, I am leaning toward an electronic glitch, either in the thermostat, the communications board, or the circuit board on the furnace. BUT, when Larry shut down the system, it reset the controls, and that could have reset the safety because of the flame rod.
Not simple to troubleshoot 1,000 away. Good links were provided, and Michael gave good info as well.

kramperD · 10-11-2011, 02:13 PM

Had similar situation in my 3400 this summer, had to have motherboard replaced....but was covered. D

The Weekenders · 10-11-2011, 03:27 PM

Mine has been doing the same thing. Narrowed it down to the sail switch but I think it is the wires leading to it. Wiggle on the wires to it and it works great for days in a row and then does exactly what you described. I pushed down on the wires to the sail switch and it works good again. I just need to get the blower cover off to inspect the conection to the sail switch. I bought a new one and might as well install it while the blower cover is off.

Larry-P · 10-11-2011, 05:46 PM

Thanks for the help.
I also spoke to the service department at Camping World. They indicated that it could also be a bad ground connection on the battery because the furnace runs on 12volts.
So far today it's been working perfect. That's the way these things are. Get ready to findout the problem & fix it & nothing goes wrong.

2Wanderers · 10-14-2011, 09:35 AM

Had an identical problem twice. Once was fixed with a new sail switch. Several times after that I have fixed it by removing the 12v DC fuse to the furnace, reinstalling the fuse, and that reset the circuit board (kind of like your computer when you dont know what else to do). I beleive you can also have issues like you describe with newly attached propane bottles and the safety valve issue. At the moment mine is working great, but the first thing I look for is the circuit board reset. I probably need a new circuit board, but I paid for an hour worth of troubleshooting labor just to be told there is not a problem. 200 miles down the road and it would not work. Called back to the dealer and no refund. Don't take it in unless it doesn't EVER work. Good luck.

Larry-P · 10-15-2011, 03:04 AM

I still have the issue with my furnace. I'm on the way home to Illinois & plan to stop at the Camping World in Council Bluffs, IA on Monday. I'll see if they can help me.
I have also found that when the furnace won't fire, if I turn the temperture up to 75 to 78 degrees the furnace will run properly. That is when I can get it to run. Not the best thing in the world but at least in the morning we can get some heat in the coach.
Hope to get this fixed soon. Let you know what is found out at Camping World.

Larry-P · 10-18-2011, 04:16 PM

On Monday past we stayed at Camping World in Council Bluffs Iowa for the day for repair of our furnace problems.
After it was decided that the furnace was covered under the warrenty, (coach is 1 month old) it was determined that the problem was the sail switch. Normally it would take a day for the part to be shipped but Camping World put the rush on & had the part delivered within hours & installed. Furnace has been working great since.
My thanks to Camping World (Sam in service department)for being understanding that we are traveling home to Illinois & got the work done ASAP.
I also found out that the sail switch is often the problem when these furnaces are acting up like this.
Glad this problem is over & we're on the road again.
Happy RV'ing to all.

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