No heat, fan is running??

[Steve38]

Mine did the same thing.
Put a test meter on the sail switch. If it does not close the circuit the gas valve will not open.
The sail switch is the first step to finding the problem you have descibed. And it is only $10.

[burnt toast]

The igniter is not snapping trying to ignite and it is plugged into the house.

[northstar1960]

so you get solid continuity over the high limit ? you can jump the leads and if it fires then you know it's the high limit .there is or should be a sail switch . looks like a paddle attached to a contact. you have to pull the unit to see it . it's located on the combustion air side . if the fan is coming on and it's not one of the items above then i would go with PC board

[burnt toast]

I will try and jumper the limit switch tomorrow never thought of that, I have the unit pulled right I don't see a sail switch I know what I'm looking for but I don't see it. Tx for the tip.

[TimVWulp]

Originally Posted by burnt toast

Suburban SF-35F model. I loosened off the fitting to purge the gas line at the furnace I am getting propane. I reset the master switch let it sit for five minutes did not help. Continuity check to Highlow switch was completed showing zero 00.5 at 68°F. There is no sail switch it appears to be electronic I'm thinking it's the board what do you think?

Hi you checked the continuity of the high limit and it showed 0.5 ohms of resistances. This tells me that the hi limit is good and that the switch in the hi limit is closed and will let electricity flow to the ignition board. If you can trace the wire from the high limit to the ignition board and you have 12 volts there to the board. If you have 12 volts and no spark the board or the igniter/flame rod has a problem.

Hope this helps Tim

[burnt toast]

Did a few more tests finally said fu** it, took it to local rv shop they're going to bench tested this week I'll follow up

[mike.t]

burnt. Been there. Life is to short. We bought these bad boy's to enjoy not to have them kick our ass. It will work out fine.

[burnt toast]

So got a call this afternoon heater is ready, I stopped in and picked it up they tell me it bench tested fine I just laughed oh of course it did. They did take it down and clean it up I guess that's better then throwing parts at, I will reinstall it tomorrow and update how I make out. Hope it fires up lol!

[burnt toast]

Well I got it reinstalled and it fired up first try haha guess it just needed a cleaning lol