Ok at 3am not much could have been running, an a.c unit refrigerator, maybe hot water heater and tv with satellite receiver, every time the power shuts off that propane detector starts beeping REALLY loud then goes off. The humming noise seems to come from the converter area. After the power shut off and came on about 10 different times finally at 6:30 this morning it came on and has not went back off. It seems that this only happens late at night or early morning......I just got here with my husband he says that it just random has been doing this for about 3 weeks now. Any ideas now?