Dry camping in the high sierras is cold at night... 30's and 40's. We learned three things:
1. There is something plastic like drill chips in the furnace. Last year it smoked us out so we did not use it. This year we ran it during the day until the burnt plastic smell got down to tolerable. Gradually over a week the smell diminished to where it no longer caused your nose to stuff up. By the second week all the plastic had burned out and the furnace was ok.
2. When it was coldest we ran the two coach batteries flat using the furnace at night. In the morning we could not start the generator the batteries were so low. Even the propane/carbon monoxide detector was showing a red light for low voltage (9v threshhold). The solution is to start the Ford engine. When the the alternator charge rate got to 13.4v., there was enough in the coach batteries to start the generator.
3. I noted also that when the temperature is near freezing at 8 to 9000 feet elevation, it was best to prime the generator with a short (3-4 second) crank, wait about 2 minutes for the gas to become vapor, then the generator will immediately pop off on the next try.