We have a central heat/air unit that just shuts off and won't come back on. We have replaced the thermostat 3 times. Each time we replace it the central heat/air works fine for a while, keeping the temp at a set number. But then the unit just won't come back on. We replace the thermostat, and it works again for a while. We were told we may need to reset the central heat unit, but have yet to learn how to do this. Anyone know?
