my heat pump blows hot air at times, then blows cold, when i remove the filter, the coil is iced up. why?

Answer 1

For some reason it sounds like the reversing valve is inoperative on your unit. In normal operation it is an AC unit which puts freon in a gas phase in the coil near the filter which removes heat from the air in your house and adds it to the coil outside which in turn heats the air outside.

When in heat-pump mode, the gas phase is moved to the coil OUTSIDE, cooling the ambient air and moving the heat to the coil INSIDE, thus heating your house. If the coil INSIDE the house ices up, you can be low on freon and/or the reverser valve can be malfunctioning. A thermostatic control may also be broken which would turn the compressor off if the airstream is too cold. Also--IS THE FILTER CLEAN?? Icing up of A/C can easily happen if not enough air moves past the coil per second. If you have a dirty filter reducing air flow, or if all vents are closed in the house, the coil can ice up. Icing during heat pump mode (heating) means the reversing valve is not working. You need a service call. Check the freon and valve.

Answer 2

It need either cleaning the coils, adding coolant or both.(plus changing the filter regular)
also yours probably is the type which needs to be put on aluxuary heat(heat strips) the heat pump is only good down to about 45 degrees after than it needs the heat strips for heating. you usually have to manually turn it to auxuary heat strips.

Answer 3

Put it on emergency heat for the weekend and schedule a service call for next week,may be low charge or defrost not working correctly,can't tell from here.

Answer 4

have the coils cleaned by a pro at least every year.

Answer 5

Dirty coils, insufficient air flow or low charge.

Answer 6

It doesn't have enough freon.