furnace wont start

[matthew NYC]

I have an Atwood 7900 series 12 volt furnace. I ran out of propane and now the fan blows for 12 seconds, tries to fire for 6 seconds. It does this three times than the fan just blows cold indefinitely. I have done this several times to no avail. Every thing else gas driven works fine. Please help. Its very cold in the north east. Thanks.

[WBCCI9898]

I'm no mechanic, however, mine did the same thing and we had to change the circuit board in the furnace. Ours would try to start but would not ignite. At first we thought it was the regulator but that did not work, we had to change the circuit board.

[eubank]

Sounds an awful lot like your running out of propane also caused the propane lines to run out "dry," so to speak.

On our rig, we generally have to get all other appliances (manual strike) to work before the fridge and heater will refire (both auto-strike). But I suspect it kind of depends on how your rig is piped.

But you're sure that there's no cut-off valve to the heater (and fridge) that's turned off, right?

Lynn

[Mike Leary]

I'd be looking at the ignitor board, replace it with a "Dinosaur" board. The furnace will
have to come out, so have them check the entire operation at the same time.
Dinosaur Electronics Home. High quality circuit boards for RV appliances.

[ScottW]

Matthew, I'm sorry but this is too good to pass up...
After you ran out of propane, did you refill the tank or is it still empty?

Seriously, try lighting the stove and let it burn for a minute or two.

[matthew NYC]

Full tank. I tried it about five times and it finally caught. It has been working well for three hours now. Perhaps only a little air stuck in the lines takes time to purge, or possibly a small piece of dirt was lodged in from the tank and was pushed thru. Either way its working and I thank you all for suggestions and will use them if I have it happens again