I have a new Carrier furnace and air conditioning system which was installed last June. We like the way it performs, the heat seems to be more even, the outdoor unit is very quiet etc. I really like the thermidistat, and I'm still learning how it functions. We use the night setback to 62 degrees, and it seems like the heat comes on about 50 minutes before the set time. Can someone explain the logic and the parameters that it uses to determine when to come on, whether to use hi heat or low heat etc.