Dishwasher Won't Drain? What to Check Before You Call

You open the dishwasher expecting clean dishes and instead there's an inch of gray water sitting in the bottom. It's an unpleasant surprise, but before you assume the worst, know this: a dishwasher that won't drain is more often a clog than a broken machine. A good number of these you can clear yourself in half an hour, and we'd rather tell you that than charge you to find out.

Start with the easy wins

1. 1Run the disposal first. This one surprises people. Your dishwasher usually drains through the garbage disposal. If the disposal is full, or the drain plug was never knocked out when it was installed, the dishwasher has nowhere to send the water. Run the disposal for a few seconds and try a drain cycle.
2. 2Clean the filter at the bottom. Most dishwashers made in the last decade have a removable filter in the floor of the tub — usually a cylinder you twist out. Pull it and rinse it. You'll often find it packed with food, glass bits, or grease. This alone fixes a lot of "won't drain" and "won't clean" complaints, and the manufacturer expects you to clean it regularly.
3. 3Check the drain basket. With the filter out, look down into the sump — the low point in the tub — and clear anything sitting in it: a chunk of a label, a bone, a piece of glass. This is where things collect.
4. 4Look at the drain hose under the sink. Where the dishwasher hose meets the disposal or drain, it should loop up high before heading down. If that hose is kinked or sagging, water backs up. Straighten any kink you find.

When it's the machine, not the clog

If the disposal is clear, the filter is clean, the hose is fine, and there's still standing water, the problem has moved from plumbing to parts.

The drain pump

Most modern dishwashers use a dedicated drain pump to push water out. When it fails — or when a piece of glass or a fruit pit jams the impeller — the water has no way out. Sometimes you'll hear it hum without moving anything. A failed drain pump is a common, straightforward replacement.

The check valve or drain solenoid

Some machines have a check valve meant to keep drained water from flowing back in, or a solenoid that opens the drain path. When these stick, you get water sitting in the bottom or refilling after it drains. It's a smaller part, but it takes a look to confirm.

A control or sensor fault

Less often, the dishwasher isn't triggering the drain because a control board or sensor is misreading the cycle. This is where diagnosis matters — you don't want to replace a pump that was fine because the real issue was the board telling it not to run.

Repair or replace?

A drain pump or valve on an otherwise good dishwasher is a clear repair. Where we tell people to think twice is an older machine that's had several issues at once — the drain problem, plus it wasn't cleaning well, plus the door latch is going. At that point you're maintaining a machine that's telling you it's tired, and the honest answer might be to put the repair money toward a replacement. We'll walk you through it either way.

How we handle it

We come out, find where the water is actually getting stuck, and fix that — not a list of parts that might be related. The service fee is $140, and it's part of the repair total if we do the work. You get a written estimate before we start and a 90-day parts and labor warranty after. Most drain repairs are a single visit.