Customer recently purchased the house advised had no trouble with ac, however when they went to turn the heat on there was no heat Customer further advise that when they would switch the fan from auto to on the fan will come on Checked thermostat wiring on the furnace board and found no problems checked wiring at the thermostat found it incorrectly wired. Rewired thermostat and restarted system. System is operational and heating the house cycled system on and off several times before departing
