CLEAN AND CHECK 2YR HEATING UNIT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. LUBRICATE ALL NECESSARY MOVING PARTS, ADJUST BLOWER COMPONENTS. CHECK MANIFOLD GAS PRESSURE AND FOR VENTING. CHECK THERMOSTAT, AIR FILTER, AIRFLOW, FAN CONTROL, ENERGY CONSUMPTION, HUMIDIFIER, AND ALL ELECTRICAL CONNECTIONS. CHECK HEAT EXCHANGER, AND HIGH LIMIT CONTROL. FIXED LOOSE OUTDOO SCREWS.