Gas Furnace systems.. Perform a tune-up and cleaning to help ensure reliable and safe operation. Inspect for cracks & deterioration of Heat Exchanger. Check and clean Burners, brush and vacuumed-ok Check and clean Air Filter- replaced 20x25x4 Check and clean ignition Assembly-ok Check and clean- flame sensor-ok Check Safety Controls-ok Check CO2-CO- okay Check electrical wiring and components-ok Check Gas valve & Gas Line-ok Check Combustion Air, intake & exhaust lines-ok Check Temperatures settings Performance-ok Check and cleaned Humidifier-not working Check and run Thermostat- operating at this time. Inspected water heater Check for water leak-no leakage at this time. Check gas valve and gas Line-ok Ran water heater, operating well at this moment. Run system, left system operating well at this moment.