I have a whirlpool quiet partner 1 dishwasher. The water will not drain completely during the drain cycle. I have to restart from the drain cycle again to drain the water completely. I have checked for restrictions in the drain hose and everything seems alright. Could this problem be the timer? The water does drain but I have to do it twice. Please help this thing is driving me crazy. The model # is DU920PWKQO
The first thing I would check is the air gap (if any) on top of the sink.
Remove the cover and the top piece and check for clog.
If there is nothing wrong then the problem is a clogged check valve (#15 on the pump & motor break down diagram).
Remove all water from the dishwasher.
Remove the bottom panel.
Remove the drain hose from the check valve (be prepared for some water on the floor).
Unscrew the check valve and make sure it’s clean.
Here are the break down diagrams for the Whirlpool dishwasher Model DU920PWKQ0
Gene.
Thanks Gene,
I will let you know how it goes.
Gene,
You are the best:)
That’s exactly what it was. I found 2 little plastic pieces inside the check valve and removed them. Now the water drains perfectly. Thanks for all your help.
Hagop Ashjian
I’m glad you were able to fix it.
Gene.
Hi,
Have same problem and symptoms of above poster. Found a little bit of gunk at the end of the check valve but I find it hard to believe thats the problem.
One poster mentioned that the check valve unscrews..are you sure? There is a tag right around the check valve stating that the valve is not to be removed from the dishwasher.
Any assistance would be greatly appreciated - model DU915PWKQ0
Yes, the check valve is screwed in and you can unscrew it for cleaning.
After you will screw it back in, put a few cups of water into the dishwasher and make sure it’s not leaking.
Here are the break down diagrams for the Whirlpool dishwasher Model DU915PWKQ0
Gene.
Gene,
my helper misplaced the screws that hold the bottom covers on, can you tell me what size i need to get from the local hardware store?
It is part number [COLOR=#0000ff]AP3084773[/COLOR] #36 on the diagram.
Thanks
This was an easy repair!
FRANCESstreet,
What is the model number of the dishwasher?
Gene.
Sorry it is a DU915PWKQ0, and I need the 4 screws that hold the bottom two plates on.
I have checked and found no clogs; any other ideas?
Can you be more specific on the problem? What is the complete model number of the dishwasher?
Gene.
[quote=Gene;14781]I’m glad you were able to fix it.
Hi Gene,
I had this problem draining and cleaning the one way valve fixed me right up. I just wanted to say thanks! 
Brian
PS For anyone else doing this, the rubber valve flops outwards. It took me a while to figure out you can run a long screw driver right through the valve to clear the blockage, just do it from the small diameter exiting through the large diameter.
Hello Gene,
Thanks for the advice on the check valve, I couldn’t let this thing whip me and low and behold I found 2 fish bones and 2 lemon seed stuck inside. Pumps like it should now. Thanks a bunch once again Gene!!!
I have the same problem with my DU920PWKQ0. I have cleaned the check valve and hose. I ran water through the check valve and it flowed fine. It’s still leaving about an inch of water left after cycle done. I have gotten all the water to drain out but had to run drain cycle 4 or 5 times. I don’t know where to go next. Can you help?
[QUOTE=SMarten;301444]I have the same problem with my DU920PWKQ0. I have cleaned the check valve and hose. I ran water through the check valve and it flowed fine. It’s still leaving about an inch of water left after cycle done. I have gotten all the water to drain out but had to run drain cycle 4 or 5 times. I don’t know where to go next. Can you help?[/QUOTE]
Where is the drain hose connected to?
If it’s connected to the garbage disposal, disconnect it and check for any clog. Make sure there is no any floating foreign objects inside the hose.
If it’s connected to the air gap on top of the sink, most likely the air gap is clogged up.
Gene.