We have a 10 year old F&P Dish Drawer. We noticed the lower drawer would start to fill, stop, wait, pump out the water, then eventually fill again (repeat). After several attempts, it would finally succeed (start washing) but of course the detergent had been washed away. I talked to an appliance repair shop and they told me the water is coming in too fast so to replace the water solenoid valves. I did. Same problem. I rotated the control boards between the upper and lower units, no change. I found the motor coil assembly for the lower unit was loose hanging (plastic rivets failed) so replaced that. NG Replaced the drain hose for lower unit. NG. Tried a new wiring harness, NG. All diagnostics pass. Replaced rotor, NG. So I'm pretty out of ideas. I'm thinking "maybe" the check-valve in the lower hose may not be working correctly but there's no more water in the lower unit than the upper after it pumps out. If I turn the water supply valve for the DW almost completely "off", so it fills very very slowly, most of the time it will work properly. I'm really out of ideas here but hope someone has seen this B4. Thanks for any advise you may have. Oh, I also have the adapter for the garbage disposer vertical with the upper unit's hose on top and the lower unit's hose on the bottom.