Preventative maintenence inspection on Carrier high efficiency furnace running in great condition. 20x25x4 air filter is new today. #35 humidifier pad in good condition. Clean flame sensor and check ignitor. Visual inspection of burners. Flush condensation trap and drain lines. Run test unit in heating mode from thermostat. Temperature rise is within specs. Blower and inducer motors tested good. Pvc flue vents in good condition and no sign of leaks. 0PPM CO detected during testing. Humidifier tested during heating mode. Dehumidifier is disabled for Winter time. Furnace and humidifier are operating properly, efficiently and ready for Winter.