AP4366551 broke, unit wouldn’t drain. Removed AP2910020 and cleaned out broken pieces. What is the little black flap in there for and how do I know if it is working propperly?
The black flap acts as the check valve. It keeps water from coming back down the drain hose and entering the dishwasher.
The flap opens up when water is traveling out of the dishwasher and then the flap seals closed if water tries to travel the other way, into the dishwasher through the drain hose.