13 POINT MAINTENANCE TUNE-UP FOR A 13YR HEATING SYSTEM. CLEAN AND CHECK BURNERS AND BURNER OPERATION. CHECK HUMIDIFIER, AIRFLOW, GAS PRESSURE, AIR FILTER, FAN CONTROL, HIGH LIMIT CONTROL, HEAT EXCHANGER, THERMOSTAT, AND ALL ELECTRICAL CONNECTIONS. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS. RENEWED SERVICE AGREEMENT.