How to Fix a Dishwasher That Won’t Drain

You load up the dishwasher, press start, and go about your evening. When you open the door expecting sparkling clean dishes, you’re instead greeted by a pool of murky, smelly water sitting at the bottom. It’s frustrating, but it’s also one of the most common dishwasher problems out there. And the good news? You can usually fix it yourself without calling a repair person or spending a bunch of money. Let’s walk through what’s happening and what you can do about it.

First, it helps to understand why a dishwasher drains in the first place. After the wash and rinse cycles are done, a pump kicks on to push the dirty water out through a hose and into your kitchen sink’s drain line or your garbage disposal unit. If that water isn’t going anywhere, something is blocking that path or the pump isn’t working properly. Most of the time, it’s a simple clog you can clear with a few common tools.

Start with the easiest fix: Check the drain filter. Every dishwasher has a small mesh or metal screen at the bottom, usually right under the lower spray arm. Over time, food particles, broken glass, bits of plastic, and even stray labels collect there. When it gets too full, water can’t flow through. Pull out the bottom rack, unscrew or lift out the filter assembly (check your owner’s manual if you’re unsure how), and rinse it under hot running water. Use an old toothbrush to scrub away any gunk. While you’re in there, look around the drain opening for anything obvious, like a piece of bone or a lodged grape stem. It sounds gross, but it’s the most common reason for standing water.

If the filter is clean and water is still there, the next suspect is the drain hose. This is the flexible plastic tube that runs from your dishwasher to the sink drain or garbage disposal. It can get kinked, pinched, or clogged with sludge. To check it, you’ll need to pull the dishwasher out from under the counter – just a few inches will do. Disconnect the hose at both ends (have a towel and a shallow pan ready because a little water will spill). Look inside the hose with a flashlight. If you see a gummy buildup, you can run a long, flexible brush through it or flush it with water from a garden hose. A common culprit is a blockage where the hose connects to the garbage disposal. Sometimes that rubber knockout plug, a small plastic disc that comes with a new disposal, was never removed, and it blocks the water flow. If you have a disposal, run it empty while the dishwasher is off. If you hear a gurgling sound, that plug might still be in place – you can remove it with pliers.

Another frequent issue is a clog in the garbage disposal itself. Food scraps can build up in the disposal chamber and then get pushed into the dishwasher drain line. Run your disposal with cold water for a minute to clear it out. Then pour a cup of baking soda followed by a cup of vinegar down the disposal. Let it fizz for ten minutes, then flush with hot water. This helps break up any greasy residue that might be causing a backup.

If the hose is clear and the disposal is clean, the pump might be the problem. Dishwasher pumps can jam if a small piece of metal or glass gets caught in the impeller. To access it, you’ll need to remove the lower spray arm and the filter assembly first. Then, look for a small cover or grate near the pump inlet. Shine a flashlight in there – sometimes you can spot a stray shard or a twist tie. Use needle-nose pliers to gently remove anything you see. If the pump still won’t spin, it might need to be replaced. But before you go that route, check the simple things one more time.

One more check: the drain hose loop. Many dishwashers have a high loop in the hose that prevents dirty sink water from backing into the machine. If that loop was accidentally flattened or pushed down when you shoved the dishwasher back into place, water might not flow out properly. Make sure the hose is routed up as high as possible under the counter, often clipped to the underside of the countertop. This creates a natural siphon that helps the pump do its job.

Sometimes the problem isn’t a block at all but an air gap. If you have an air gap on your countertop near the sink (a small chrome cylinder with a little cap), it can get clogged with debris. Remove the cap and clean out the inside with a toothpick or pipe cleaner. Gently push any gunk out, then replace the cap and run a short cycle to see if the water drains.

If you’ve tried all these steps and the water still isn’t moving, you might have a faulty drain pump motor or a bad check valve. Those are less common and require a bit more technical know-how, but they’re still doable for a confident DIYer. You can find replacement parts online for your specific model. But for most households, standing water is just a clog waiting to be cleared. Give these fixes a try – you’ll be back to clean, dry dishes in no time, and you’ll save yourself a service call.