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