Dan Musicant wrote:
there's one they can hack into with saws. Presumably they'll repair.
They say they'll install ducting (2"). What it actually says on the
form he gave me is "Add new (if required) PVC 2" flue system up to
10ft." The heating system is rated at 95.5% AFUE (efficiency). The
form says "Seal ducting system to current Title 24 standards as
required by law." He said this included pressure testing.

Red flag; inconsistent comments. 2" ducting would be tiny.

Check. I was wondering that (the 2"). What's inconsistent there?

The 2" flue is probably 2" PVC pipe for the combustion air and exhaust to/from
the furnace. That's what they use for high efficiency furnaces.