My crawlspace drain backed up raw sewage into the HVAC return
Last Sunday in Raleigh, I went down to swap out the furnace filter and stepped in an inch of black water that smelled like a sewer plant. Turns out the exterior French drain pipe had clogged with roots and the sump pump couldn't keep up, so it pushed everything back through the floor drain. I spent 8 hours with a shop vac, bleach jugs, and a drain snake before calling Roto-Rooter at 11pm because the smell was getting into the living room. Has anyone else had a backup ruin their ductwork underneath like that?