We bought a 20 year old home with the original Trane heat pump. It worked fine all winter. I set the temp at about 68/69 and the temp was within a degree or two throughout the house all winter. (we have a 2 story colonial, seems well insulated, thermostat on 1st floor).

We had a few days here in the 80's. I set the temp at 72. The 1st floor cooled to that no problem. The upstairs though is closer to 80! It seems I need to set the thermostat to 65 or so to get the upstairs cool...but then its too cold downstairs. When the weather warms again, I will close off some vents on the first floor, perhaps that would help....I seem to recall them being closed when we biught the home in the fall last year---then again, the owner had one closed in a bedroom upstairs too....they are all open now.

Why would it work so well in the winter cold but not the spring warm? Might it work better when we constantly get temps in the mid 80s to 90s. The air blown is icey cold.