Issue with suburban furnace in 2012 cedar creek 5th wheel

[cz-sp01]

first thanks in advance. 2012 cedar creek 5th wheel with suburban furnace and digital dometic dual mode thermostat. 2 ac unit that work fine. I live in south Louisiana so this past week we got cold weather so I went and put the furnace on 40 just to keep everything from freezing. went in the next morning and the furnace was not running and it was 32 in the camper. I turned off and turned on the furnace. nothing. I increased the temp. nothing. I then checked the furnace fuse in the panel. I pulled the fuse and it was not blown. when I put the fuse back in the blower of the furnace came on and then it started blowing hot air. so I thought things were fixed. next morning I went back in the coach and found the same thing. the temp was colder than what the thermostat was set on. so I pulled the fuse again and put it back and the furnace blower kicked on again and then it started blowing hot air again. obviously it is staying on for one cycle then not coming back on. any help would be appreciated. I used the furnace in October and it worked fine.

[cz-sp01]

ok everyone. i'm a dumbass. I checked the propane tank that was on and it was completely empty. apparentliy this furnace ran all night and sucked all the propane out of that tank. my bad. I turned my other propane tank on and the thermostat still would not control the furnace. there is a telephone wire connected to the back of the digital dometic thermostat. I disconnected that wire and put the fuse back in and the blower came on and then the gas kicked on then the unit started putting out heat like normal. I turned the gas off and let the blower stop by itself. then I pulled the furnace unit out of the camper. (suburban model SF-35Q). I checked the sails switch and it worked. I checked the high limit switch and it worked. I cleaned the terminals on the control board. I checked both the solenoids on the gas valve and they were fine. I could not find the relay delay switch. my guess is that its built into the control board. so I put everything back together. re-connected all the wires. thermostat is still completely disconnected. I turned the service switch (next to the blower) back on and then put the fuse back in and the blower fan kicked back on. After a minute I pulled the fuse to stop the blower and shut it down for the day. I'm assuming its not the thermostat since the blower would come on with it being connected. So that leaves the control board. any help is appreciated. thanks in advanced.

[dougrainer]

newman fulltimer wrote:
Bad overheat limit switch keeps locking the furnace out or the regulator is bad causing it to run to hot

Bad overheat switch will not close/reset just by pulling the fuse and reinstalling the fuse. Possible problem is just a bad ignition module. Bad modules will run and shut down but not restart the 2nd cycle. BUT, you SHOULD be able to turn the furnace OFF at the wall tstat and restart the wall tstat and the furnace will engage that first cycle then stop. Pulling the fuse will do the same thing as turning the tstat ON and OFF. Doug

[cz-sp01]

Both tanks are full and turned on.

[donn0128]

Did you turn the gas on? And do you have gas in the tanks?

[newman_fulltime]

Bad overheat limit switch keeps locking the furnace out or the regulator is bad causing it to run to hot

[BFL13]

Sometimes our furnace wouldn't get going again unless the thermostat on/off switch was turned off and back on for the 12v. Same thing as your pulling the fuse and putting it back in. Cure for us was to get a new thermostat.