So brief backstory: I had a partially clogged kitchen drain, which took a significant amount of snaking/plunging/boiling water to clear. But it is now cleared and draining quickly. The slow drain was discovered because my dishwasher stopped working. Just running the faucet did not produce enough water volume to back up the drain, but when the dishwasher pumped out its water it backed up into the sink.

My dishwasher (Whirlpool WDF520PADM3) still won't run. Behavior is: it fills up with water, it drains (presumably to test the drain speed?), then it fills again, then it just sits there.

From the diagnostic mode, it reports the following error codes: 6-4 (float valve open) and 8-1 (drain too slow). However, the float valve moves freely and appears to be working (when I pull it up manually, I can hear the relay switch click), and when the dishwasher drains (e.g., if I fill it and then manually enter drain mode), it drains freely without backing up.

I have tried "resetting" the dishwasher (it is hard-wired, so I turned it off at the breaker for a few minutes and then turned it back on), to no avail. If I start it up, the behavior is the same.

At my wits end here. Any help or additional troubleshooting steps would be greatly appreciated. It's almost like it's stuck in some error mode from when the drain was clogged and I can't get it to reset.

Thanks!

* Quick update ... so I "reset" it again, and when I start it up (in 1-hour wash mode because the damn thing takes like 4 hours to run through a normal cycle), it fills and then makes a noise that I would describe as bullfrog-esque (the pattern is duh duhduh). I can hear the clicks that I assume are the dishwasher attempting to switch cycles and then it just makes that bullfrog noise repeatedly. I turned it on, let it be, and come back 2 hours later and it's just sitting there full of steaming hot water baking food onto my dishes for the 13th time.