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. Recommended a blower wheel cleaning, electronic air cleaner and humidifier. Installed EAC and tested operation. Blower wheel in furnace is dirty reducing air flow/efficiency, pulled and cleaned blower wheel. Reassemble and tested operation. Declined the humidifier at this time.