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. Air distribution system is dirty reducing airflow and efficiency. This creates longer run time and increased utilities cost. Air filter is dirty. Humidifier is also in need of a tune up. All options declined at this time.