We live in a large three bedroom apartment that is heated by ceiling coils. I have no idea how to use the heat. Do I turn on the heat and leave it at a low setting all the time and then turn it down at night? We used to do that with our thermostat when I was growing up. 70 during the day 68 at night. This has few numbers on a dial 50, a line,"comfort zone" another line and then 90. Any help would be greatly appreciated.