Classic Winnebagos & Vintage RVs

My 27' '89 Chieftain's furnace still refuses to light. It worked well last Fall before parking for the Winter. Now only the fan comes on without any heat. Underneath valve is open as well as the propane tank valve and the propane is about half full. I tried to light the furnace with the generator running.  Any ideas?

John

If the fan comes on you have power to both the thermostat and the control board. Generator won't make any difference.
Some things to try:
Turn on and light the burners on the stove top and check the quality of the flame. This will tell you if you have fuel coming out of the propane tank and indicate somewhat the pressure. It is possible to have a partially plugged regulator or line.
Check the electrode alignment on the furnace. You will have to pull the actual furnace from its shroud. Fairly easy, turn off and purge the propane, disconnect it at the furnace, disconnect the wiring harness at the board and remove the one outer hold down screw from the furnace and pull it out of the shroud. Full instructions in the manual section here.
Some - call first to check - dealers/servicers can bench test the board.

Whatever you do, follow ALL safety directions, particularly regarding checking for propane leaks before trying ignition.

The manuals here are quite helpful.
There are also a few members here whom are quite knowledgeable concerning propane appliances. Far more knowledgeable than I.

Could be the sail switch has something catching it, like a mud dauber nest, or spider webs, or just lint.  Those little buggers like to hang out in the furnace.

Quote from: HandyDan on February 10, 2018, 10:38 PM
Could be the sail switch has something catching it, like a mud dauber nest, or spider webs, or just lint.  Those little buggers like to hang out in the furnace.

Also a possibility, and there are more. Again, good choice is the manual section here. It will let you determine how far you are comfortable in testing on your own, when to ask for advice, and when it may be time to bite the bullet.

Have you read through the appropriate procedures for your furnace?

Pilot Model RV Furnace (http://www.classicwinnebagos.com/forum/index.php/topic,2640.msg5110.html#msg5110)

Direct Spark Ignition Model (DSI) (http://www.classicwinnebagos.com/forum/index.php/topic,2640.msg5112.html#msg5112)