I'm trying to extend the height of my 20 year old Heatilator chimney. It's a solid pack insulation 8" ID chimney (IC8 series part numbers.) Heatilator no longer makes this, and none of the distributors in their database have any old stock. Does anyone have any ideas of how I can proceed? I'm looking for someone who might have a part (I need 36", IC836 or equivalent pieces), or whether there's an alternate chimney I could use to replace the whole thing. I'd prefer not to replace the fireplace, which is a Heatilator FP36 (woodburning) from 1985.