Dishwasher Not Draining? 5 Common Causes and Solutions

A small amount of water in the bottom of your dishwasher is normal — it keeps the pump seals lubricated. But if you open the door and find several inches of dirty water that won't drain, something is preventing water from exiting the machine.

Dishwasher drainage problems range from simple clogs you can fix yourself to pump failures that need professional repair. Here are the five most common causes, from easiest to most complex.

Most modern dishwashers have a removable filter at the bottom of the tub. When food debris, grease, and sediment clog this filter, water can't reach the drain pump. This is the most common cause of dishwasher drainage issues and the easiest to fix.

Fix it yourself: Remove the bottom rack, locate the filter (usually a twist-and-pull cylinder), and clean it under running water with a soft brush. Clean the filter monthly to prevent buildup. Also check for broken glass or debris in the filter well.

If your dishwasher drains through the garbage disposal (most do), a clogged disposal or a new disposal with the drain knockout plug still in place will prevent the dishwasher from draining.

Fix it yourself: Run the garbage disposal for 15–20 seconds to clear any food buildup. If you recently installed a new garbage disposal, make sure the dishwasher drain knockout plug was removed during installation.

The flexible drain hose connects your dishwasher to the garbage disposal or sink drain. Over time, this hose can kink (especially if the dishwasher was pushed back too far) or develop internal clogs from grease and food buildup.

What to check: Pull the dishwasher out enough to see the drain hose. Straighten any kinks. If the hose is visibly clogged or corroded, it should be replaced — a quick job for a professional.

The check valve prevents drained water from flowing back into the dishwasher. When it sticks closed, water can't drain out. When it sticks open, dirty water flows back in. Both scenarios leave standing water in the tub.

Check valve replacement is an affordable repair that's best handled by a professional since it involves accessing the drain pump assembly.

The drain pump uses an impeller to force water out of the dishwasher. If the pump motor burns out or the impeller breaks, the dishwasher fills and washes but can't drain. You may hear a humming sound (the motor trying to run) or complete silence during the drain cycle.

Drain pump replacement is a common repair that a technician can typically complete in one visit with parts on the truck.

Scrape food off dishes before loading (no pre-rinsing needed). Clean the filter monthly. Run the garbage disposal before starting the dishwasher. Use a dishwasher cleaner monthly to break down grease buildup in the drain path. These simple habits prevent most dishwasher drainage issues.

Can I use Drano in my dishwasher?
No. Chemical drain cleaners can damage dishwasher components including the pump seals, hoses, and stainless steel interior. Use a dishwasher-specific cleaner or a vinegar rinse instead.

Why does my dishwasher drain but leave some water?
A small amount of water (about a cup) in the filter well is normal — it keeps the pump seals from drying out. If there's significantly more, the drain path may be partially clogged.

How much does dishwasher drain pump repair cost?
Drain pump replacement is a mid-range repair — significantly less than buying a new dishwasher. Our diagnostic fee is waived when you approve the repair, and you get a full quote before we start.