Lennox Gas Furnace system maintenance 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. x1) 20x25x1 provide by customer 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- possibilities of failing Check Combustion Air, intake & exhaust lines-ok Check Temperatures settings Performance-ok Check and clean condensate water traps-ok Check and clean condensate pump- washed out. Check and cleaned Humidifier- ok Hum water panel- ok Check and run Thermostats- System is having an issue to run. Spoke with technical support need to check and confirm gas pressure @ furnace, furnace is also giving error code for hot surface igniter. It was recommended for igniter to be replaced. Follow up is need to replace H