ahh so giant air restrictive cardboard installation instructions and screws and the like aren't supposed to be wedged back into the coil before slapping it on top of the furnace??? lol these guys must be pushing the fiberglass filters ...
why replace furnace when hx was still under warranty??????
I know this thread is a little old, but...
On a Lennox G-23 (that is what model started the thread), I would ask the HO if they would consider replacement of the furnace to go up to high eff., and because most G-23's with all original parts would probably need: a new ignition control to replace the Johnson control one, a new blower cap, and quite often a new board (caused by the weak cap). (I've seen all of the above on one furnace. $1300 later, one person had me fix it .)
Then tell them that I would HAPPILY replace the HE for them if they would like. (3 or 4 hours flat-rate time for a very easy replacement.)
I always like to give the customers their options. Future repairs on an old pos furnace, or a new one with a warranty. Sold a lot of new equipment this way. No pressure, just options.
And a second thank you for the pics. I also show these to students to show them the right vs wrong way.