Updated almost 7 years ago on .
coil replacement in furnace
I recently bailed on purchasing a 4-plex I was going to rent out. The ages of the furnaces were as follows: 25+ years, 17 years, 17 years, and 19 years. Apparently, the coil had been replaced in 3 of them. Each furnace still worked. Is replacing the coil a viable option to extend the life of a furnace?