OnOtto
Menu

Why is there water in my dishwasher, and how do I drain it?

Updated August 2026

30–45 minutes · Moderate DIY

← All how-to guides

Standing water at the bottom of a dishwasher is a clog until proven otherwise, and four checks solve most of them in 30 to 45 minutes: the filter and sump, the garbage disposal it shares a drain with, the disposal knockout plug if the disposal is new, and the drain hose plus its high loop. All four cost nothing but time. Only after those come up clean are you looking at a failed drain pump or a stuck check valve, and that is a $150–300 repair call.

What you need

Before you start: Kill the breaker before you reach past the filter. A dishwasher tub holds water directly above a 120-volt pump motor, and the door switch is not a disconnect. Broken glass hides invisibly in gray sump water, so bail with a cup instead of sponging by hand, and wear a glove for the last of it. Never pour chemical drain cleaner into a dishwasher: it does not reach the clog, it attacks the pump seals and the plastic sump, and it turns your next bail-out into a chemical burn risk.

Steps

  1. Switch the dishwasher off at the breaker before your hands go in the tub.
  2. Bail the standing water into a bucket with a cup, then finish with towels or a wet/dry vac. Expect 1 to 2 gallons, and check the door gasket channel while you are there.
  3. Twist out the filter and the flat screen and clear them, then lift the sump cover if your model has one. Follow the same routine as cleaning a dishwasher filter and pull out every seed, chip, and label.
  4. Restore power, run the garbage disposal for 30 seconds with the tap on, then start a rinse-only cycle. The dishwasher and disposal share one drain, and a slug of food in the disposal chamber backs straight into the tub.
  5. If the disposal was installed recently, pull the dishwasher drain hose off its inlet nipple and look inside with the flashlight. A molded plastic knockout plug ships in place and has to be punched out with a screwdriver, then fished out of the disposal chamber so it does not lodge in the pump.
  6. Trace the drain hose under the sink. It must rise to the underside of the countertop and clip there, or run through an air gap on the sink deck, before it drops to the disposal. A hose lying flat holds dirty water and lets it siphon back.
  7. Twist off the air gap cap and cover, if you have one, and clear the debris packed into the chamber. This single part explains a surprising share of no-drain calls in newer kitchens.
  8. Disconnect the hose at the disposal end into a bucket, flush it out, and squeeze along its length to find a crushed section. Replace any hose that stays kinked.
  9. Listen on the next cycle. A pump that hums with no drainage, or stays silent entirely, means the drain pump or check valve is the fault, and that is where DIY stops being economical.

Or hire it out

An appliance repair tech charges $150–300 for a no-drain diagnosis and clear-out, and $250–450 if the drain pump itself needs replacing, since the part alone runs $50–120. On a machine over 8 years old, get the estimate before you agree to the work.

Done. Now the part everyone skips: doing it again on schedule. Log it in OnOtto and the next reminder for dishwasher drain fixes sets itself.

Log this task, get the next reminder

Frequently asked questions

Is a little water in the bottom normal?

Yes, up to about a cup sitting in the sump recess is by design. That reservoir keeps the pump seals wet and stops them drying out and cracking between cycles. What is not normal is water covering the tub floor, water above the filter housing, or water that smells sour because it has sat through several cycles. If you can see the filter poking above the waterline, you are looking at a design feature, not a fault.

Why does dirty water from the sink end up in the dishwasher?

That is backflow, and it means the drain hose has no high loop or working air gap. Without a rise above the sink drain level, sink water follows gravity into the tub. The fix is free: unclip the hose, run it up to the underside of the countertop, and strap it there. It is also a plumbing code requirement in most jurisdictions, which is why a home inspector flags it on sight.

Will vinegar and baking soda clear the clog?

It deodorizes and it will not hurt anything, but it does not move a wad of food out of a sump or a hose. The fizz reaction is gone in seconds and generates no real pressure. Mechanical removal is the fix: hands, filter, hose. Save the cup of vinegar for the empty hot cycle you run once everything drains again, where it does earn its place.

At what point do I replace the machine instead?

Use the age line. Dishwashers run 9 to 12 years, so a $400 pump job on a 10-year-old unit buys uncertain time, while the same repair on a 4-year-old machine is easy math. New units install for $600–1,200 for a solid mid-range model. Check your unit against how long a dishwasher lasts and the thresholds on how often to replace a dishwasher before approving anything major.

Related