I think it's better to allow the heatpump to run continuously and use a good t-stat to cycle the aux based on the indoor temp.
The better stats don't work based on a fixed differential.
...when the cop drops below 2 it's probably not worth while.
i agree that hp is better than elec heat but there is a time when running the hp its a waste of powe
General public's attitude towards our energy predicament: "I reject the reality of finite resource depletion and substitute it with my own; energy is infinite, we just need an alternative storage medium to run the cars on. The economy can grow indefinitely - we just need to "green" everything! Technology is energy! Peak what?"