PERFORM 13 POINT MAINT. TUNE-UP FOR 6YR HEATING UNIT. CHECK HUMIDIFIER, ENERGY CONSUMPTION, AIRFLOW, AIR FILTER, FAN CONTROL, HIGH LIMIT CONTROL, HEAT EXCHANGER, AND ALL ELECTRICAL CONNECTIONS. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. ADJUST BLOWER COMPONENTS AND LUBRICATE ALL NECESSARY MOVING PARTS.