Preventative maintenence inspection on standard efficiency gas furnace running in great condition. 20x25x1 air filter in new condition. Clean flame sensor and check ignitor. Visual inspection of burners. Test ran in heating mode from thermostat. Temperature rise is within specs. Blower and inducer motors tested good. Galvanized B-vent in good condition and no sign of leaks. 0PPM CO detected during testing. System is operating properly, efficiently and ready for Winter.