Stupid Q: Troubleshooting a Dishwashers Drain

It seems to be a common problem that dishwashers, sooner or later, will leak massive water over the floor. I’ve been told that the drain line often requires some loop or arc in it to prevent a siphon effect, I believe…and far too often they are not installed with such. Also, some will argue food particles clog the line if you do not rinse your dishes.

Regardless, examining my dishwasher’s drain line, it appears to run uphill into the disposal under the kitchen sink…a common plan. But, drains typically work by gravity-flow, therefore dishwashers must have a pump in the drainline, correct? If so, how well does the pump handle food particles? Could the pump be the real culprit here to leaking dishwashers that don’t drain well? (I should mention there is a standing puddle in the bottom of my dishwasher at the end of a run.)

I know my parents had the same problem, but I forget what the cure is! I do recall that pre-washing dishes helped, but it’s hard to get all family members into that routine! - Jinx

The dishwasher drain hose should, typically, arch over near underside of counter top and connect to a side tee pointing downward into the sink drain as high as possible above the “U” or “P” trap.
Dishes should be ‘scraped clean.’ Small food particles are not a problem for the pump.
Your drain hose may not be installed correctly if it back siphons water from the drain

I think that at least some dishwashers have built-in grinders (essentially mini garbage disposals) that chew up the crud before it can clog the pump. Others may have filters to catch the more egregious stuff.

So I’d investigate to see if you have a clogged filter. It’s possible that your pump is bad. If, as you say, your line is “running uphill” to the disposal, is it possible that it was clipped higher and the clip has broken?

Another thing to check is if the hose has a kink in it where it bends. We had one like that long ago, and I used a small C-clamp to unkink it.

This is a great site for troubleshooting appliance problems.