PDT750SSF1SS GE Dishwasher Won't Drain

DClark

Premium Member
Joined
Jul 15, 2019
Messages
3
Location
Norman, OK
Model Number
PDT750SSF1
Brand
GE
Age
6-10 years
I think it's about 7 - 8 years old. We use it a lot--usually a load a day, but it seemed to be working fine.
A few days ago, after a wash cycle there was about 3/4 inch of water in the tub. First, I cleaned out the filters. They were pretty bad. I won't let that happen again.
I then ran a rinse cycle to test it and it pumped out so I thought it was OK. Ran a full cycle that night and this time again, it left too much water in the tub. There was evidence of a little over-flow out the door.
I pulled out the unit and checked the sink and drain tubing. The first thing I discovered was that there was a drain loop under the DW sound insulation in addition to the one I had installed under the sink. (according to the installation instructions). Don't know if that's a problem. There was a dark area inside the drain line, so I took it out and flushed it with a garden hose.
I tried another Rinse Cycle and watched the drain during the drain cycles and it was just dribbling. The drain pump was running, with the unit out, I could clearly hear it and feel it but it never put out more than a trickle for more than a half second. Again, too much water in the tub. Then, I noticed the flood switch still had some crud in it that may have been impeding the float, so I cleaned that, thinking I might have a fix here. No luck though. Again, just a dribble from the drain line.
Through all of this, the wash-action sounds like it is pumping with decent flow.
Thanks in advance for any suggestion or thoughts on this.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
101,322
Location
McMullen Valley, Arizona
Hi,

If the drain pump was running but your only getting a trickle coming out the drain hose, then I'd remove the drain pump and see if something is clogging it, or if the impeller is stripped inside it.

Here's the drain pump for your model:

Let us know what you find.

Jake
 

DClark

Premium Member
Joined
Jul 15, 2019
Messages
3
Location
Norman, OK
Hello. Thank you for your prompt response. I really appreciate it. I didn't remove the pump before because there was a crimp-type clamp holding it to the sump outlet.

Do you normally have to cut those clamps off? Can they be replaced with a normal clamp? Also, do you know if there's a way to force the controller to run the drain pump? I would like to try it without running another rinse cycle and getting more water in the tub.

I'm thinking about probing it with a pipe cleaner from both ends. If that doesn't do it I'll try to remove it and clean it as well as I can. I tried to disassemble the pump but it did not seem to want to come apart. There may have been another screw under the little electronics enclosure on the pump. I was hesitant to get too rough with it. Thanks again for your help.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
101,322
Location
McMullen Valley, Arizona
Yes, cut the crimp clamps off and get a normal radiator clamps.:)

Here's the service manual:

Place unit in Service Mode on page 22. LED blink#1 turns the drain pump on.

The drain system starts on page 82 and it tells you how to remove it on page 84.

Now some of the early models used a TCO(Thermal Cut Off) line break for the drain pump, if yours has the TCO ohm test that first. Remember to make sure the breaker is off to your dishwasher!

Jake
 

DClark

Premium Member
Joined
Jul 15, 2019
Messages
3
Location
Norman, OK
Hello again.
Many thanks for your help with the drain problem. Replacing the drain pump did the trick. I'm guessing that the impeller was slipping on the shaft. Can't say that for sure, but the pump motor was running and I had opened the pump to verify the impeller was turning.
So, it's draining just fine. But now, it's not heating. The wife won't use it like that and I'm inclined to agree. It shows fault F16 "High Water Temperature". Thermistor is 240 ohms at room temp where it should be 11k according to the manual. (Thanks again for sending that. It's been very helpful.)
I don't mind replacing the whole flood switch assembly if it's not too many $. If you agree with my diagnosis, I'm hoping you can give me the part # for the flood switch assembly. I tried looking it up on the website but what I was finding didn't seem right for my model. The part number you gave me for the drain pump was spot-on, so I'm hoping for similar success with this one.
Thanks in advance and kind regards,
Darrel
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
101,322
Location
McMullen Valley, Arizona
Ok Darrel, glad to hear the new drain pump fixed the NO DRAIN PROBLEM. (y)

Correct, your flood switch is bad if your own getting 240 ohms at room temperature.

Here's the flood switch for your model you can order:
WD21X10519 Switch Flood Asm


Let us know how it goes.:)

Jake
 
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