Two years ago, we condemned a Goodman 80% in an attic. We bid it but never heard back. Today I got a call for no heat only to arrive and find this:

That's odd, this appears to be a 90% GoodMana. It's also butchered in, badly. The electric is being supplied by a chopped off extension cord. It's not even secured to anything, just hanging there. There's no drain trap on the furnace as required by Amana. In fact, the furnace is so close to the attic floor that the trap CAN'T be installed. The ductwork is a mess. Check this out:

The return trunk runs alongside the back of the furnace and takes the turns as shown. Also - note the stack pipe that's been taped over instead of properly capped. The HWT still vents into that 8" stack, and the return is not sealed, so when that tape dries up and falls off, flue gases can recycle.

Also (not shown), no intake pipe on it, so it burns attic air. It's also in an unconditioned space, so if it shuts down in below freezing weather the drain is going to freeze.