Dishwasher losing water during cycles

Dishwasher Repair
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This model is a timed fill, no flow meter. It does have the soil sensor. Solenoid works fine, float is clean underneath and operational, pump is free and clear, inlet water screen is clean, 1/2" valve at the main is wide open, I pulled the rubber flapper and it appears fine, no obstructions holding it open, and when it fills it fills fine, “when it fills” being the key words here :mad:…

Here’s the issue:

Just recently I noticed our dishes were not getting cleaned. I went through the unit and cleaned the screens, chopper, etc… thinking that was part of the issue, dirty but not excessive. This didn’t help what so ever.

I noticed that during a “normal cycle” setting (the setting we almost use exclusively) the pump sounded strange right after the detergent release and when I opened the door I found the sump empty, bone dry. Now, according to the cycle operation chart for this unit it is not supposed to drain until well into the cycle, so I shouldn’t be losing water to the drain and refilling (or should I?). Basically it will lose water and not refill for the 20min wash cycle. I will find a partially broken up detergent pack sitting on the bottom of the washer 9 times out of 10.

This said, it will work once in a while, this is an intermittent problem. I will more less have to start the cycle and listen for the sound of flowing water, if I don’t hear it I have to fill the sump manually using a pitcher of water, then it works fine.

I have all the tools to diagnose this issue, meter, tools, etc.. I am a HVAC tech by trade with 20yrs on the job, I just need you guys to point me in the right direction here. I can post any pictures or video you need to assist in diagnosing this problem, just let me know what you need.

Thanks in advance for any help you can provide. :slight_smile:

I have included a pic of the cycle chart with a note of where I am losing water.

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A little more info…

Here is what I got, hot off the press, just happened not 30min ago…

We load up the washer with some heavily soiled dishes and start the “normal” cycle.

The unit fills fine, goes through the “prewash” then stops… Then goes into a drain cycle… Then tries to fill and go into a wash cycle with no water in the sump.

So I open the door and bring the sink nozzle over to the unit (one of those nozzles on a hose) and try and manually fill the sump… It would not fill. Run downstairs to the drain hose and water is pouring out as fast as it’s filling.

This said, the drain pump was NOT running, the door was open.

So I know of two things that keep water in when it’s supposed to stay in… The drain hose loops up to near the top of the dishwasher creating a trap, I checked and the hose is sitting up high. The other thing is a small rubber flapper that acts as a check valve for the drain pump. I checked and there is nothing holding it open or wedged in there.

So I canceled the cycle and restarted it with a empty sump… First thing it does is refill and it fills just fine and holds…

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Did you ever solve this? I have a Maytag MDB8959SBS2 that has started exhibiting the same problem.