GE dishwasher GTD630PYR3FS draining but not completely

[clavius]

Hi All,

My GE dishwasher, model GTD630PYR3FS, S/N ZT761402B has recently started failing to completely drain at the finish of the cycle. We first noticed that the dishes were not quite drying completely and before long the inside of the tub was starting to look moldy. I removed the strainer at the bottom of the tub and found that there was water standing in the little drain sump where the filter locks into. It is still above the level of the inlet to the drain pump. You can see that in the attached photo. 

This is what I have done thus far:

- disconnected the drain hose to check for obstructions and partial clogs. It appeared clear and I went as far as first blowing air through it and then sucking back through it with a wet vacuum. The small amount of water that the air blew into the drain looked clear and the vacuum drew no debris out. 

- the washer discharges into a rarely used disposal. There is no backup in the drain. When the washer gets to a drain portion of its cycle, the drain motor is clearly running (based on the sound) and I can see a strong solid stream of water discharging into the disposal and continuing down the drain.  

- I check that the routing of the drain hose has not changed and the hose has not moved from where it has been since the washer was installed a few years back. It does not have a separate air gap (the disposal is essentially that), but loops up to above the point where it empties into the disposal as it always has. It is the same drain set up that has been on this washer since it was installed and is the same one the previous washer used for 20+ years. 

- thoroughly cleaned the drain sump at the bottom of the tub and cleaned the course and fine strainers to be completely clean. 

What you see here is after I had vacuumed out all the water, cleaned the strainers and everything else up and ran a single standard cycle with "boost dry". When the cycle was complete, the inside of the washer was still wet and this was what was left in the drain sump. 

A couple of questions please: Is there a check valve or similar device that prevent water from coming back in from the drain line once the drain motor shuts off? Looking at the parts diagram I am not seeing anything obvious, but suppose it could be integral to the drain pump assembly. Is there something else I should be checking or looking at? 

I would appreciate any insight before I go blindly changing parts or whatever. 

Thanks very much!

 

[clavius]

And I neglected to mention: there are no error codes indicated on the control and the machine has all the appearance of working OK otherwise. 

 

Thanks again...

[Alanna Farrell]

It sounds like you've done a thorough job troubleshooting so far—nice work ruling out clogs, hose positioning, and drainage performance. Given that water remains in the sump after a full cycle and the drain motor appears to function properly, one possibility is a failing or stuck check valve (sometimes integrated into the drain pump assembly) that's allowing water to backflow into the dishwasher after draining. Even though it's not clearly labeled on the parts diagram, many GE models do have a flap-style valve either in the drain pump outlet or the drain hose itself near the pump. If that valve is degraded or not sealing fully, it can allow residual water to return once the pump shuts off. You might also consider inspecting the drain hose near the pump for any hidden obstructions or slight kinks that could slow full drainage. If everything checks out and the sump still doesn’t fully empty, replacing the drain pump assembly (which includes the internal valve) may be the next best step.