My upstairs unit is a heat pump. It is not yet 6 years old. Recently, it has been giving me problems. The blower will turn on, but it doesn't seem to put out heat or cold. Does that make any sense? We have had both cold days and hot days in the past few weeks. On the cold days, it can't seem to heat the house even if the thermostat is set to 80 or so... the temp is only 60 or so (and I assume that is because of the heat rising from the lower floor because that unit works fine). Now that we have switched over to the AC, it isn't cooling the upstairs. This weekend, we kept dialing the temp lower (down to 60 or so) and the coolest it got upstairs was 75-80 (and that was in the middle of the night). What part of a heat pump system can be damaged that would result in both the ac and heat having problems?

Is the outside unit running? If it is and still does not work call for service.

If your outside unit isn't running check the circuit breaker.

To get heat out of a heat pump, in addition to the blower, you must have the outside compressor and fan going and the reversing valves in the right position. The outside unit has a breaker in the panel plus a disconnect outside at the unit. The relay coil must have power from the thermostat.

There is a sticky at the top of the heating forum that has more details that may help.