Preventative maintenence inspection on standard efficiency American Standard furnace running in good condition. Trane Clean Effects pre-filter cleaning. #35 humidifier pad in good condition. Clean flame sensor and check ignitor. Visual inspection of burners. Test ran in heating mode. Temperature rise is within specs. Blower and inducer motors tested good. Flue vent is solid. 0PPM CO detected during testing. System is operating properly, efficiently and ready for Winter.