Fellas,
Thanks again for the advise and comments.
Sylvan, My lincensed plumber said the chimney has to be relined because it appears to have some cracks.
The guys at the plumbing supply house told me relining would cost about as much (maybe more) as the increase in cost of thru the wall appliances.
The recommendation was to reline the chimney and use the simpler heaters with less control systems for a more trouble free installation.
I will be using a lincensed chimney installer for the lining, but I would like to know my options so I can discuss the work intelligently.
Art: You mentioned 6″ corrugated metal pipe. The talk is about using stainless steel but if aluminum is less expensive would this be acceptable?
Do you have any opinion about putting filler between the pipe and chimney? I have no idea how much more this will cost, but if I don’t need it, I don’t want it.
Thanks again to all.