Always on. I guess I have always just taken it for what it is, never thought about the dangers, although this post makes me realize there are dangers in leaving that on. In my opinion, if I am concerned, the easiest thing to do would be to go into the camper and simply turn the fridge off just before refueling. You wouldn't just want to shut the propane tank off as the fridge would continue to draw propane until it runs out, and then you could get some air into the lines which would require the fridge to reset several times before getting ignition. I think simply turning the fridge off would be safe to do. I fuel with diesel which has a much different flash point, and not so flammable vapors, so I don't think I will be turning the fridge off if I am able to fill at the RV or diesel islands without gas vapors close, but this is a good option.
Loving our Sierra 365SAQ
Nights camped so far in 2016 = 0
Although Many trips scheduled.