No Heat

A low battery will cause the sail switch not to open, but I imagine you'd still hear the igniter?

Just noticed then the trying to start the heater there is no clicking noise. The clicking usually heard when he gas is being lit.

So maybe the igniter has gone back or there is a fuse I haven't found yet. What to you all think.

No gas smell inside or outside the trailer. Just made a nice pot of coffee on the stove. Heater fan comes on but gas doesn't light. Checked fuses but don't think a fuse controls the propane flow.

Do you have a propane stove top? If yes, turn it on to see if the problem is propane supply. If stove works, then the problem is the furnace.

gas smell?
ensure your tanks are on. I always like to light the stove top before, seems the quickest to get the air out of the lines.
I know once, our fuse came loose in the fuse box, the red light was barely flashing. I pulled the fuse out, here the **** spot where the fuse connects into the box, came loose. I pinched it back down with needle nose and worked ever since.

Trailer has two propane tanks. One tank run out last night and the second tank was not turned on. Turn on the second tank and the heater ran for 3.5 hours. The second tank is full or was 3.5 hours ago.

So I wouldn't think there was air in the line.
Shouldn't be out of propane.
Propane is turned on.

I'm lost for ideas.

Propane can freeze. At about -305F.

If you have any water in the line (not likely) it will freeze at 32F.

Is there air in the propane line?
Are you out of propane?
Is propane turned on?