SERVICE TUNE-UP ON 15YR HEATING SYSTEM. FIRST CLEAN AND CHECK UNDER SERVICE AGREEMENT. CLEAN AND CHECK BURNERS AND BURNER OPERATION. LUBRICATE ALL NECESSARY MOVING PARTS, AND ADJUST BLOWER COMPONENTS. CHECK THERMOSTAT, AIR FILTER, HEAT EXCHANGER, HIGH LIMIT CONTROL, FAN CONTROL, HUMIDIFIER, AND ALL ELECRICAL CONNECTIONS.