I own a 2011 Big Country 3450TS (purchased 5 Oct 12), that is currently parked in a full time lot in Dickinson, ND. I have it very well insulated and all lines wrapped, and have had no problems even in negative temps. Then I went south for Christmas, and left the BC in place while I was gone. To prepare for my trip, I turned the main water supply line off, but kept water in the lines; flushed the septic out and put 5 gallons of fresh water in the tank with a smell good additive; turned the heater thermostat down to 50, and felt i had done all I needed to do. Everything was working perfectly until I returned yesterday. I drove straight through (17 hours) and walked in at 0130 hours to a camper that was colder inside than out. Thankfully, everything else is working, so I turned the fireplace on, put a space heater in the bedroom and Miles (my mini-schnauzer) and I slept pretty good. Guess the years in the infantry helped me there, while his fur and sweater helped him. Anyway, I feel I have checked everything out and need some help. I got the water lines thawed to find a major leak behind the toilet, so with the water turned back off, and as we're under the covers sipping bottled water, I am considering the furnace and what may have happened. I've recycled the thermostat as told to do by the manuals...nothing. The propane is flowing perfectly, as the stove works, the hot water heater works and I am hooked up to a new 250 gallon tank. There is clicking when I turn the thermostat on and off and when I try to get the blower to work, I hear a hum...so...everything seems to want to work, but I can't get the blower to work. ? Have hung a 75 watt bulb over the unit downstairs, and could really use some advice here. Anyone have a similar problem or ideas that may help me? My fiancé called from her nice, warm southern home and said she had heard something about a sail switch? Huh? What and where is that? Thanks so much...appreciate any ideas and feedback.