If I could go back and change my mind, I would never install a gas furnace. I hate our gas furnace in our beach house now. Furnaces last around 10-15 years with good maintenance. I am hoping that my four year old gas furnace will die prematurely. I hate it so very much. The reasons for this is that the gas furnace is terribly inefficient. The gas furnace starts up and blasts at max capacity then shuts totally off. This is the worst way to maintain comfortable heating. I should have a heating system that keeps a steady flow of warmth. It will wear out components by  turning on and off continually. Also the gas furnace is the type of heating system that negatively impacts air quality. The heating system pulls in all of the dirt from the carpets, air quality and curtains. Then the dirt is pumped back out through the air ducts in the home. I am always getting headaches, sneezing and coughing due to this. The gas furnace is quite delicate as far as reliability. I seem to always have a heating contractor over to check out the heater. They troubleshoot the gas furnace, replace filters, clean the blower, and check the fan motor belt. The gas furnace always malfunctions. It has developed rust, needs parts replaced, or it overheats and won’t start back up. I have spent a ton of money because of  heating repairs and I know I could have just updated to a new gas furnace. Right now, I am just stuck with the current one. I spent my savings to keep it running. I have it hooked up and don’t want to deal with an installation project. Eventually though, I hope to replace it with radiant floors. I can’t wait to have a new heating system.