Most dishwashers stop draining because of a simple clog — usually in the filter, the drain hose, or the garbage disposal connection. Work through those three in order, then check the air gap if your sink has one; only after all of those does a failed drain pump or drain valve become the likely cause.
Clean the filter and sump
- Remove standing water you can reach
Use a cup and towels so you can work without water spilling everywhere.
- Take out the bottom rack and unlock the filter
Most filters turn counter-clockwise to release — see our filter cleaning guide for the full process.
- Rinse it and clear the sump
Food particles, seeds and small debris collect here and can stop water passing through.
Check the drain hose
The drain hose carries wastewater from the dishwasher to the sink drain or disposal. A kink, a pinched section behind the machine, or a blockage inside it produces standing water and gurgling during the drain stage. Pull the machine forward carefully if needed and check the hose runs freely along its length.
Check the garbage disposal
If the dishwasher drains into a disposal, a clogged disposal can block it. Run the disposal clear first, and on a new installation confirm the disposal’s knockout plug was actually removed. See our jammed disposal guide if it will not run.
Check the air gap
| Part | What to do |
|---|---|
| Air gap cylinder on the sink or countertop | Twist off the cap and clear debris with a stiff brush |
| Drain loop (no air gap) | Confirm the hose rises high under the counter before dropping to the drain |
A quick run-through to try first
Run the garbage disposal, clear the filter basket, and try a baking-soda-and-vinegar flush through the sink drain. If water then drains, the clog was in the shared drain line rather than the dishwasher itself.
When it points to the drain pump
If the filter, hose, disposal and air gap are all clear and the dishwasher still holds water, the drain pump or its valve is the likely cause. A silent motor during the drain stage, or a humming pump that moves no water, both point there — and so does a persistent drain-fault code. See our error-code guides for GE, Whirlpool and Frigidaire dishwashers.
When to call a professional
A confirmed failed drain pump or valve is a parts replacement best handled by a technician. See our dishwasher repair cost guide for where this typically lands before you decide between repair and replacement.
