CLEAN & CHECK HEATING UNIT TO MAKE SURE EVERYTHING IS WORKING PROPERLY. CLEAN & CHECK BURNERS AND BURNER OPERATION. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS. CHECK THERMOSTAT, AIR FILTER, HUMIDIFIER, AIRFLOW, ENERGY CONSUMPTION. CHECK HEAT EXCHANGER, HIGH LIMIT CONTROL, AND ALL ELECTRICAL CONNECTIONS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. NEW SA.