Preventative maintenence inspection on Tempstar furnace. Replaced 16x25x1 air filter. 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. 4" 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.