I have set my automatic thermostat to 68 F at night. Recently, I was working late into the early morning and I realized that the heater kept coming on and off in about 10 minute intervals. Yet, when I looked at the Thermostat, it said the temperature was 68 F.

Why does it continue to come on if the temperature is what it is programmed to be? Do I have a bad thermostat?

Any help would be greatly appreciated. I can't afford this!