We have a 2006 Sprinter, Copper Canyon fifth wheel and owned it since new. Furnace has worked well until the start of last fall. Prior to the trip I always test everything before going and ran furnace for about 1-2 hours of time and ran fine. Arrived at campground aound lunch and at dinner time turned on heat and furnace would not come on. blower yes, ignitor yes,heat no. 3 times then lockout, tried again and put hand over intake and furnace actually turned on, ran through cycle and upon start of next heating it would not start again, smell gas out of exhaust so i know its getting gas. used second heat source for that weekend. came home and cleaned furnace and it ran fine. Just went on first trip of 2013 and same problem occured with furnce, worked when temperature was 50 to 60 outside but doesn't work when temperature drops below 45 degrees. I have spent hours reading posts and researching and think the control board is the issue. looking for help

Is it getting propane? May take sometime to purge air from lines if you changed out tanks.Do you hear the ignitor clicking?

When the control board gets power (after fan runs, sails witch makes up, thru high limit switch) power is then applied to gas valve AND spark electrode.Gas flows and is suppose to be ignited by spark electrode.....then when flame is established the spark electrode is used as flame proof.If you smell gas......valve is opening BUT is not igniting either because of no spark OR electrode is not properly positioned1/8" gap between electrode and ground rod plus electrode needs to be in flame pathYou might also need to clean furnace/burner again......mud daubers/spiders/debris can really mess up the combustion air flow

Could be a regulator issue...some times they allow gas to flow but restrict it such that the furance won't work...had an issue with mine very similar...but when I switched to my other propane tank it worked!! Some problem internal to the regulator.....my stove worked fine....regardless....and so did the hot water heater...only the furance didn't like it!!

Could possibly be the sail switch. If the furnace thinks the blower is not running it shuts off.

Check all the registers, make sure they are not blocked either. Registers cannot be closed off.

Surburban Sf-30f furnace | Good Sam Community

enblethen
Nomad
Apr 30, 2013
Is it getting propane? May take sometime to purge air from lines if you changed out tanks.
Do you hear the ignitor clicking?
Old-Biscuit
Explorer III
Apr 30, 2013
When the control board gets power (after fan runs, sails witch makes up, thru high limit switch) power is then applied to gas valve AND spark electrode.

Gas flows and is suppose to be ignited by spark electrode.....then when flame is established the spark electrode is used as flame proof.

If you smell gas......valve is opening BUT is not igniting either because of no spark OR electrode is not properly positioned
1/8" gap between electrode and ground rod plus electrode needs to be in flame path

You might also need to clean furnace/burner again......mud daubers/spiders/debris can really mess up the combustion air flow
rreynold51
Explorer
Apr 30, 2013
Could be a regulator issue...some times they allow gas to flow but restrict it such that the furance won't work...had an issue with mine very similar...but when I switched to my other propane tank it worked!! Some problem internal to the regulator.....my stove worked fine....regardless....and so did the hot water heater...only the furance didn't like it!!
Ronandpat
Explorer
Apr 30, 2013
Could possibly be the sail switch. If the furnace thinks the blower is not running it shuts off.
TakingThe5th
Explorer
Apr 30, 2013
Check all the registers, make sure they are not blocked either. Registers cannot be closed off.
Degman
Explorer
May 01, 2013
furnace runs fine all the time it seems to be 50 to 60 degrees, any temperature below it, the furnace does not light, smell gas, here clicking, blower running but know ignition. i will check electrode for gap and clean furnace and try again. It's a cold weather problem only right now, and that's when it's needed the most.
enblethen
Nomad
May 01, 2013
Check the electrcial connections. Pay close attention to the one on the circuit board.
TakingThe5th
Explorer
May 01, 2013
Degman wrote:
i will check electrode for gap and clean furnace and try again.

Look the burner and orifice over carefully when you clean it. Something as small as a spider web could cause the problem. Watch the gasket when you remove the plate, the gasket is fragile but reusable. Take it off before vacuuming otherwise it will be sucked up immediately.
Degman
Explorer
May 02, 2013
thanks for all the help. pulling out this weekend and hopefully find problem
woodworker59
Explorer
May 02, 2013
Pull it out and bench test. If it runs right it is your regulator and/or pigtails. I had a problem with mine when temp dropped below 45 degrees. Hope this helps. Dave