On Nov 25, 8:12*am, "Stormin Mormon"
wrote:
*I think you mean the chimney is way too large.

Yes I did.


That said, I've helped install flue liners, for the
water heater, in the cases where people put in
a 90 percenter furnace.

Yes, that's one very practical solution. But it's also
one of those things that adds to the installation cost
of the furnace. Assuming of course you don't just
ignore it to win the bid.