The value of a used furnace depends on the age, energy efficiency and condition of the furnace and its parts. A website like Furnace Parts USA can help determine the value of a used furnace by comparing the market price of used furnaces and parts online.
As newer, more energy-efficient furnaces are made each year, older furnaces become less valuable as a whole unit. Pieces and parts of older furnaces are broken down and sold to repair existing units or for scrap metal. The value of an older furnace depends on the condition of the parts and may vary based on location and demand.