O.K. so we are sitting in the rig last night with the fireplace on and a little box heater cranking ( it got down in the 40's last night in Fl) and all of a sudden the fantastic fan desides to kick on. The first thing I asked the DW, was the thermastat on ?? and she said no. So I got up on a chair and manually closed the vent. A few minutes later it opened by itself again and wouldn't shut off. I ended up pulling the fuse ( cause I wasn't smart enough to just turn the dial on the fan to 0) till this morning so I could check into it. After tearing into it and looking at everything and cleaning everything nothing seemed to be out of place except for a little moisture on the doam. I called Fantastic fan and the guys I talked to was GREAT and very helpful walked me through everything and said I did everything right, he did say excessive moisture could of made the fan come on even if the thermastat was off. I guess tonight I will put my vent pillow up there to keep the moisture out of the vent. Just an FYI, sorry for the long post.