Fix a Dishwasher That Won't Drain

Water pooling at the bottom of your dishwasher is one of those problems that feels bigger than it is. The machine isn't broken; something is just blocking the path water needs to take to leave. That path starts inside the tub, moves through the filter basket, goes down the discharge hose, and empties into either your kitchen sink's drain or a separate standpipe. When water stops moving, it's because one of those three points is clogged, kinked, or disconnected. The good news is that you can diagnose and fix almost all of these problems yourself in an afternoon with basic tools and no special skills. The key is working methodically—start inside the machine, then follow the hose, then check where it connects. You'll find the problem, and when you do, the fix is straightforward. Once water drains again, you'll understand exactly how your dishwasher moves water, which means you'll spot trouble early next time.

1. Empty the dishwasher and remove standing water. Open the door fully and scoop out any visible water with a cup or small container. If water is deep, use a wet/dry shop vacuum to pull it out—this is faster and cleaner than bailing by hand. Set the vacuum to pick up liquids, not debris, and work from the lowest point of the tub. Once most water is gone, you're ready to access the filter.
2. Locate and inspect the drain filter. Look at the bottom center of the dishwasher tub. You'll see a cylindrical or square plastic cage or basket—that's the filter assembly. It typically twists counterclockwise to remove, though some models have a clip or latch. Check your manual if you're unsure, but most filters come free with a quarter-turn. Remove it completely and hold it up to light.
3. Clean the filter cage. Rinse the filter under hot running water and brush away any food particles, grease, or buildup with an old toothbrush. Pay attention to the fine mesh areas and the underside. If it's heavily caked, soak it in hot water with a few drops of dish soap for five minutes, then scrub again. Some filters have a secondary fine-mesh screen that lifts out—remove and rinse that too. Once clean, set it on a towel.
4. Check the drain line beneath the filter. With the filter out, look straight down into the hole it was sitting in. You should see a small opening or sump area. Shine a flashlight into it and feel around with your fingers (carefully) or a straightened coat hanger. Pull out any debris—bits of food, broken glass, plastic pieces, or grease clots collect here and block the drain pump. This is often where the real problem is hiding.
5. Trace the discharge hose for kinks and clogs. Access the underside of your dishwasher by opening the kick panel or cabinet door below it. Look for the rubber hose running from the machine toward the sink or wall. Feel it along its entire length—it should be soft and pliable, not kinked or flattened. If it's bent sharply, straighten it gently. If it feels hard or clogged, disconnect it at both ends and run hot water through it or push a plumbing snake through to clear the blockage. Reconnect securely with hose clamps if they're loose.
6. Verify the drain connection at the sink. Follow the discharge hose to where it connects to your kitchen drain. It may loop up under the sink and connect to the side of the drain pipe, or it may go into a standpipe (a vertical plastic tube). Check that the connection is tight and that there's no blockage where the hose meets the drain. If the connection is loose, tighten the clamp. If the sink drain itself is clogged, the dishwasher won't drain either—run the sink and listen for slow drainage or full blockage. If the sink is slow or backed up, clear the kitchen drain before running the dishwasher again.
7. Reinstall the filter and run a test cycle. Put the clean filter back into the dishwasher, twisting it clockwise until it's snug. Close the door. Run a short rinse-only cycle (or a full wash cycle without dishes) and listen for the drain pump to engage. You should hear water moving and draining. Open the door when the cycle ends—the tub should be empty and dry. If water remains, the pump itself may have failed and you'll need professional service.
8. Clean the kitchen sink drain to prevent future backups. Even if the dishwasher drains now, a partially clogged kitchen drain will eventually slow or stop the dishwasher again. Pour a kettle of boiling water down the drain, followed by half a cup of baking soda and half a cup of white vinegar. Cover the drain opening with a cloth for 15 minutes, then flush with another kettle of boiling water. This breaks up grease and buildup before they become a real problem.