Last year I replaced the old Honeywell thermostat in my home with a programmable one. I figured that the set back feature would save me some money during the heating season. I don't think it did. Then this summer I kept using this thermostat for the cooling season, but I kept it at a constant temperature. My heat pump seemed to run for only a short time, but it ran often. The temperature in the house never changed from the setpoint, which is what I assume a digital thermostat is supposed to do, but I became a bit concerned about the constant cycling of the heat pump and I decided to switch back to the old thermostat (mercury type) a few weeks ago. Within a few hours the humidity in the house dropped 12-15 % to about 40. This never happened with the programmable thermostat. Now back in the winter, when I set the thermostat back, it seemed that when it returned to the "normal" setting it always ran for a few minutes, then it called for the auxiliary heat.
So it is my opinion that setting back a thermostat on a heat pump is really not a viable option because the resistance heat required to raise the temperature cancels the savings attained during setback hours. And that precise control during the cooling season doesn't allow enough run time to properly reduce the humidity in the residence.
Anyone else share these views?