Furnace repair. Checked and found that the thermostat was faulty. Replaced the thermostat with an Aprilaire 8466. This customer is a Comfort Club member under the name Tom McBride. The customer's history was not in the database. Need to check and correct this issue for the customer. Also, need to call the customer to collect for the repair. The system is operating normally at this time. Completed heating preventative maintenance check for the customer and changed the filters as well.