CLEAN AND CHECK HT. CHECK THERMOSTAT, CHECK HEAT EXCHANGER, CHECK BURNERS AND BURNER OPERATION, CHECK HUMIDIFIER, CHECK ALL ELECTRICAL CONNECTIONS, CHECK HIGH LIMIT CONTROL, CHECK GAS PRESSURE AND FOR PROPER VENTING, CHECK AIR FILTER. LUBRICATE ALL NECESSARY MOVING PARTS, ADJUST BLOWER COMPONENTS. HAD TO REPLACE CAPACITOR UNDER WARRANITY. EVERYTHING IS RUNNING GREAT.