Similar problem Chickendoc has. The pemperature lebel shown in the thermostat is 67 while the setting is 72 when it stops. The furnace run short period of times. Some times it re-starts a few times stopping/re-starting succesively at same period of times. Finally, it gives up. What we are doing is lower the setting bellow the actual temperature and then we setting it up passing the actual temperature. We hear the starting "click" and system starts again.

The thermostat is an about two years old digital "Ritetemp" and the gas furnace is an about five years old Amstron Ultra V Tech 80.

Thank you


Eugenio

Check the furnace for any status/diagnostic LEDs.