My ProHeat unit is not working properly, AGIAN!! It is icing up when I use the AC, AGAIN!! If I take it to a shop I will get one of the same 4 answers, problem #1: not enough freon, problem #2: too much freon, problem #3: not enough ventilation, or problem #4: all of the above. The unit seldom works for more than 3-4 months without something going wrong and that is not counting all the belts that break. NO Carrier repair place has been able to make this thing work for more than a month or two. Anyone with any insight as to what I can do with this thing? Anyone want to steal it off of my truck? Layoutshooter