The furnace is running good, no issues, ready for the winter. I checked the furnace, cleaned the air filter, and checked the thermostat. I also checked the gas line and the pilot light. I tested the thermostat and the furnace to ensure it was working properly. I also checked the air ducts and the vents to ensure they were clear. I also checked the furnace's burners and the heat exchanger to ensure they were working properly. I also checked the thermostat's wiring and the thermostat's batteries. I also checked the furnace's electrical connections and the furnace's gas valve. I also checked the furnace's safety features and the furnace's warranty.