Heat Pump Operation

[mwdilday]

OK I have a hunch why the fan may be cycling on heat. When the outside air temperature is colder the unit efficiency is drastically effected. When this happens the air from the registers is cooler and will eventually, if it gets cold enough outside, be nearly as cold as the air entering the returns. I expect this unit has a sensor on the outside coil that turns the fan off if the coil gets too cool and then turns the fan back on after it heats back up. This will eliminate the "cool" air coming from the vents.