What a rip off. 10$ a foot. An aluminum expandable 4” dia, pipe
for a liner. Now (NYS) required to line the chimney when you
replace the (90%+) furnace with a direct (PVC) vent. Because
the chimney will not have both furnace and hot water tank using
the flue, the moisture content could deteriorate the flue. :-(
Well during the summer months the furnace isn’t using the flue
either, and the flue has been fine for over 50 years. Probably
longer than that accordion aluminum pipe will last…