Performed annual Furnace precision tune up; clean and tune up furnace; clean burners, test ignition components, adjust gas level, test safety circuit, check indoor motors, checked all electrical components, tested indoor air flow, checked heating temperatures, and tested overall furnace operation. Pulled and cleaned blower fan Torino increase airflow and efficiency of unit. Dirty fans also create more stress on variable speed motor and may shorten life of motor. Recommend motor surge protection to prevent electrical breakdowns external from motor. Now that unit is out of warranty, motor is very expensive repair if it fails.