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. Collector box is leaking and recommended replacement. Vent starter is leaking oil and recommend replacement. Blower wheel is dirty and recommend cleaning it. Also recommend a surge protector and electronic air cleaner. Ordered collector box and gasket and will return to replace. Blower wheel in furnace is dirty reducing air flow/efficiency, pulled and cleaned blower wheel. Reassemble and tested operation. Replaced vent starter and tested operation. Installed electronic air cleaner and tested operation. Surge protector was declined