I checked in with Customers. I set up my 8' ladder under return grill . replaced the 20x30x1 filter . checked Honeywell digital Thermostat . Thermostat is hard wired (no batteries ). climbed up into the master bed closet attic access. removed and cleaned burners, cleaned off flame sensor electrode. Inspected the hot surface igniter . test the blower motor 5mfd run capacitor . regulated natural gas pressures to 3.34 in w.c. pulled temp rise 45° 75° return / 120 supply . pulled amp draws on all mechanical components . The Lennox 97% Furnace is operating at factory recommended specifications Job Complete