I have tried vinegar and baking soda and a commercial cleaner. When I use the plunger the water in time will go down. What should I do first? Should I take my dishwasher apart or the attempt to clean the trap? Thank you for your help!

  • The diagram below is good in theory, but horrible in fact. The hose should be angled up as much as possible under the sink & have NO SAG like the picture very poorly & wrongly displays. That sag is what lets debris into the hose to clog it in the first place. Loosen the "high rise loop" bracket, pull the hose to remove all sag & retighten the bracket. A "special" no-pressure-push Air Gap isn't needed unless & until the law says so & MOST of those are incorrectly installed with a sag in their hose. Air Gaps are worthless & a mistake in my book.
    – Iggy
    Commented Jan 18, 2016 at 14:42
  • @Iggy There is actually one very good case for an air gap - two dishwashers that drain to the same garbage disposal dishwasher inlet will very easily back up into each other even with a high loop because the same pump that can push over one high loop can push over the other one too.
    – Moshe Katz
    Commented Jan 17, 2018 at 20:38
  • Maybe, but the few I've done had a Wye fitting that connected right at the disposer to address any such potentiality. Never had a problem with those few and 1 I went back to a year later to re-plumb the drain pipes for a new dual sink was still scrubbed clean and clear. I just haven't seen anything but problems with air gaps, a very flawed device and bad idea.
    – Iggy
    Commented Jan 18, 2018 at 13:58
  • From plunging, I am pretty sure we got shredded chicken in to the hose. Eventually, I used my air compressor to blow it out. Man that was gross. Make sure that hose is clear the entire way.
    – Evil Elf
    Commented Sep 28, 2021 at 17:30

2 Answers 2


It sounds like your dishwasher drain line is not installed correctly. You should have a loop so the drain line goes above the bottom of the sink before it goes to the dishwasher. Generally, the loop is attached to the bottom of the countertop itself.

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Without the loop, when water is draining from the sink, it will naturally flow down the dish washer line. If there is a restriction in the sink drain, it will make things even worse, as the dishwasher drain is likely to the path of least resistance.

The loop prevents water from draining down the line so long as the standing water level is lower than the high point of the loop. If your sink is almost completely full of water without the drain stopper in (to the point it drains into the dishwasher), you have an upstream clog that must be dealt with either way (you'll have the same issue with the dishwasher draining into the sink and/or not draining at all).

  • How does water in the bottom of the dishwasher drain if the drain hose goes so high?
    – Mzzzzzz
    Commented Aug 27, 2016 at 2:38
  • 2
    @Mzzzzzz pumps.
    – hazzey
    Commented Jan 1, 2017 at 1:53

I don't see any reason it would be the dishwasher. The drain or, if you have a a disposal, is plugged up. The bottom of the dishwasher is the low point and so it backs up mostly there instead of into the sink. The drain needs to be cleaned for a proper flow. With a disposal the dishwasher outlet may go into the disposal and it could be the disposal that is plugged. In any case, it's best to also have an air-gap installed. Essentially the hose from the dishwasher goes up to a device that protrudes above the counter or sink such as through a hole for a rinse wand. Then another hose goes to the plumbing or garbage disposal. That air gap above sink level prevents water backing up into the dishwasher and prevents a vacuum sucking water back into the dishwasher. It's required in some states. However, it still may be slow to drain from the sink until the line is properly cleaned out. It could be the disposal, trap, or something further down the line like cooking grease.

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