I have a condensation problem somewhere in the main air shaft around my Quattro furnace, model # MAA 080 NR4R. I think a drain must be clogged, maybe an overflow of the drip pan possibly? Anyway I'm trying to find a schematic to know where to look. This unit was installed on the main floor, not in the attic.

I do not have the answer to this, however, I have the same problem. My initial thought is that the unusually high humidity has caused condensation. I would also be interested in seeing a schematic. If you get hold of one, please post. Thank you