I have been doing business with Wolverine Heating & Cooling for quite some time. They just came out and did a seasonal checkup on the furnace. I have them do that on a regular basis and generally have not had any problems in between Spring and Fall. I highly recommend joining their annual program. My furnace is about twenty years old and is still operating okay. You do not want to have to replace it until it breaks. Wolverine Heating & Cooling keeps the system running at about ninety-percent efficiency. Today, most new furnaces can get about ninety-five to one hundred percent efficiency. So mine is doing pretty good! The technicians are always very personable and do a fine job. They do not dilly-dally around. They do what has to be done and go on their way. Generally, I am usually there and the techs can answer all of my questions or concerns. Last year we had quite a humid winter. I did not think that the system was working very well and it was dry most of the time. I checked it out and it still had water in the humidifier and was working fine. You should set it around seventy percent if the humidity is around forty-five to fifty percent. The company's prices seem to be competitive compared to everything that I see advertised on television or wherever. As far as I am concerned, Wolverine Heating & Cooling has always been fair-priced for what I have to have done. I have already been recommending them to people and definitely will continue using them since I am very satisfied.