[kschmeck]

Standing water in tub at bottom is dirty and overflowing small basin. There is no apparent food debris at tub drain opening. The unit has worked fine in past, but lately does not rinse the dishes clear. There is no air gap, but the drain hose to the garbage disposal (working fine) is 18"+ high. It appears there may be a clog in drain hose or at tub basin bottom. Question: May I safely use Drain-o or Liquid Plumber in a dishwater as long as I rinse it thoroughly with an empty dish cycle afterwards? Thanks.

[denman]

May I safely use Drain-o or Liquid Plumber in a dishwater as long as I rinse it thoroughly with an empty dish cycle afterwards?
I would not use either product as they will eat some plastics.

Undo the drain hose at the house plumbing and let it drain into a pail.
Be sure to hold the hose firmly and put a towel over the pail so water does ont splash all over.
Check where the hose attaches to the house plumbing this is a common place where debris collects and plugs the drain.

Here are your parts
Replacement parts for General Electric GSD3230F00WW Dishwasher | AppliancePartsPros.com

Remove the sump cover (center of the tub) and check it for debris or anything wrapped around the chopper. Be careful as there is often broken glass in the sump.

A common problem with these units is the piston and nut (Item 564 in Section 2). It is behind the rear filter assembly in the tub. It unscrews.
Remove it and check that it is sealing.
What happens if it does not seal correctly is that during drain some of the water goes back into the tub instead of out the drain.