Defrost Icing Problems - American Standard Heat Pump
by adam kiger
This unit is an American Standard heat pump, 2.5 ton 13 seer, R-22. It ices up every time it is 42 degrees or colder and raining outside. The refrigerant charge is good with 10 degrees F of superheat. It also has new board and heat pump defrost sensor on it. I think the rain freezes on top of the unit but they always cut it off before I get there. I have noticed that there are a lot of these American Standards that are operating like this this year. But mainly this one is having the most problems. It does have an 10 year older Trane air handling unit on it.