Our Whirlpool DU811SWKU0 has again determined it will not pump down, at all. The local appliance guy has restored the collector / check valve X2 with positive results lasting about 9 months per visit. I pulled the unit and opened the collector to find a black ring gasket loose against the screen at the top of the collector. The parts diagram indicates this part belongs in this area, however it likely is in the wrong position.
What recomendation could you present?
Answer Martin, You'll want to remove the collector and valve, and soak the assembly and all the components in hot water and either distilled white vinegar, or a product like "lime a way", CLR, etc. Make sure all the components in the assembly are clean and free of any deposits or debris. When you reconstruct the collector replace the seals 8520843 3369177 ( you could use a couple of small "dabs" of rubber cement to hold the gasket(s) in place, while installing the assembly). Make sure there are no twists or kinks in any of the hoses, including the drain hose