Turn off the propane tanks.
Does it still go off?
I had that problem in my 1181.
With all windows open it would go off night or day.
Replaced it and the new one would also go off after a few hours.
Replaced that one too. The newest one would also go off after a few hours.
Went to Walmart, bought a battery operated Co2 carbon monoxide detector and mounted it in the sleeping area.
It went off too after a period of time (less than a day).
WTF? Took the battery operated Co2 detector into the house (all windows shut) and it was fine. No false alarms.
The problem was that it was in Arizona, it was warm/hot and the camper windows were open all the time. Either pollen or dust was setting off the detector.
I pulled the fuse, relocated the camper to a different climate, re-installed the fuse. All was well.
Tree pollen in the PNW is at the "Very High" level right now. It could be the cause. ??
