Preventative maintenence inspection on Comfortmaker standard efficiency gas furnace running in great condition. 20x25x1 air filter 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. Galvanized B-vent is a great condition and no sign of leaks. 0PPM CO detected during testing. System is operating properly, efficiently and ready for Winter.