MAINTENANCE TUNE-UP ON A 7YR HEATING UNIT. PURCHASE A NEW SERVICE AGREEMENT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK THERMOSTAT, AIR FILTER, HUMIDIFIER, AIRFLOW, ENERGY CONSUMPTION, FAN CONTROL, AND ALL ELECTRICAL CONNECTIONS. CHECK MANIFOLD GAS PRESSURE AND FOR PROPER VENTING. CHECK HEAT EXCHANGER AND HIGH LIMIT CONTROL. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS.