A couple of years ago I was camping with my sister/brother in-law sitting around a nice late September campfire. It was getting a little chilly so my sister decided to go into her Jay Feather LGT 29N to turn on the furnace, and once the furnace started she came back out to the campfire. This was the first time the furnace had been turned on since the prior spring.
About ten minutes later someone screamed that there was smoke coming from her 29N, so I ran into her TT grabbing the fire extinguisher and immediately seen the source of the smoke.....the cold air furnace vent. Once I got to the vent I could see flames behind it and unloaded the extinguisher through the vent louvers. I had the flames out in about 5 seconds, then headed back outside to pull the shore power and turn the LP tanks off.
All said in done, we confirmed that there was no signs of heat building up in the walls, so we just opened up all the widows so the TT would air out. My sister stayed in my TT that evening. I took the following photos the next morning after removing the furnace vent cover:
The TT was taken to the Jayco dealer and they determined that the root cause was a mice nest
. The entire furnace had to be replaced.
So, if your furnace has not been in operation for an extended period of time, when first starting it up give it a little run-time before leaving it unattended.
Oh, another great mouse nesting area....., behind the microwave.