Preventative maintenence inspection on Carrier high efficiency gas furnace running in great condition. 20x25x1 air filter in good condition. Check again in 1-2 months. Clean flame sensor and check ignitor. Visual inspection of burners. Flush condensation trap and drain lines. Run test unit in heating mode. 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 pad in good condition. Open damper and set controller to 40%. All systems are operating properly, efficiently and ready for Winter.