and the end of the day i have been blowing out my twin resin dis and pump and reels with a compressor this way nothing in the van can freeze no matter how cold it gets .in the morning i fill my tank with hot water from the house , my tank is only 250 which is enough to keep me going till lunch time or so until the temp rises then i just fill it on up with cold till i finish i dont see why all the di only guys are not working like this or even the ones with a ro going di only until cold snap passes