On Dec 28, 9:37*pm, fzbuilder wrote:
Will not stop running at all even with thermostat to off. I have to
hit the breaker. It will run all night if I don't

Is it the blower that runs, or are you generating heat and the blower
is running. If the blower continues to run when the temperature of
the blowing air is cool, then the sensor that shuts off the blower is
defective. On older furnaces, as a previous poster said, there is a
temperature sensor that has ordinary metallic contacts that sometimes
stick. If you whack the side of the furnace and the blower stops, it
is probably sticking contacts. Newer themostats have electronic
controls that I don't know much about because I have an older fuirnace.