I don't know if this is the right forum to post in- but I'm living in casper this winter in my 5th wheel and this morning I woke up to no heat! my furnace wouldn't come on when I turned the heat up. I...
It may be cold enough that there is an insufficient vaporization rate to support the demand the furnace places on the propane supply. Adding a heating pad may help.
It is also possible that the converter can't keep the battery charged enough for the fan speed to activate the sail switch. If it is a modern converter--try it with the battery disconnect switch to store (off).