CLEAN AND CHECK HT. CHECK THERMOSTAT, CHECK HUMIDIFIER, CHECK ALL ELECTRICAL CONNECTIONS, CHECK AIR FILTER, CHECK GAS PRESSURE AND FOR PROPER VENTING, CHECK HIGH LIMIT CONTROL, CHECK HEAT EXCHANGER, CHECK BURNERS AND BURNER OPERATION. ADJUST BLOWE COMPONENTS, LUBRICATE ALL NECESSARY MOVING PARTS. EVERTHING IS RUNNING GREAT.