I have used Repco on several occasions to clean and repair my furnace. After having used several services in the area, I found that the guys at Repco are by far the best in the HVAC space. They are fair and do a thorough job. After the cleaning or repair they do an excellent job at recommending next steps. If you are in need of HVAC services in the northwest suburbs, Repco is the only service provider I would recommend using.