1ST MAINT. CHECK-UP UNDER SERVICE AGREEMENT FOR 6YR HEATING UNIT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. ADJUST BLOWER COMPONENTS AND LUBRICATE ALL NECESSARY MOVING PARTS. CHECK HEAT EXCHANGER AND HIGH LIMIT CONTROL. CHECK THERMOSTAT, AIR FILTER, AIRFLOW, HUMIDIFIER, ENERGY CONSUMPTION, FAN CONTROL, AND ALL ELECTRICAL CONNECTIONS. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING.