Dishwasher Not Draining? How to Fix It
Short answer: Check the sink side first: run the garbage disposal, clean the air gap cap if you have one, and look for a kinked drain hose. Then pull and rinse the filter in the bottom of the tub. On a newly installed dishwasher, the disposal's knockout plug may still be in place.
- Difficulty
- Easy
- Time
- 20 to 45 minutes
- Updated
- November 9, 2026
What is causing it?
Most drain problems are clogs: a dirty filter, a clogged disposal or sink drain, a blocked air gap, or a kinked or sagging drain hose. On a new install, a disposal knockout plug that was never removed blocks drainage completely. A failed drain pump is less common and needs service.
Tools and materials
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Tools
- Towels and a shallow pan or cupTo bail waterCheck price on Amazon
- FlashlightCheck price on Amazon
- Soft brushFor the filterCheck price on Amazon
- Screwdriver and hammer, for a knockout plugCheck price on Amazon
Materials
How do you fix a dishwasher that won't drain? Step by step
Run the disposal and sink
Built-in dishwashers usually drain through the disposal or sink drain. Run the disposal with water to clear it, and make sure the sink itself drains well.
Clean the air gap
If there is a small chrome cylinder on the sink deck, pull off its cap and clean out debris. Whirlpool lists this as a common fix.
Check the drain hose
Under the sink, look for kinks or a crushed section. The hose should loop up high (a high loop) or connect to an air gap so dirty water cannot flow back.
Clean the filter
Turn off the dishwasher, bail out standing water, and remove the filter from the floor of the tub (usually twist and lift). Rinse it, brush off residue, check the sump for glass, seeds or labels, and lock the filter back in fully.
New install? Check the knockout plug
If the dishwasher is new or the disposal was just replaced, the disposal's inlet may still have its knockout plug. With power to the disposal off, disconnect the drain hose at the disposal and knock the plug into the disposal with a screwdriver and hammer, then remove it from inside with pliers.
Run a short cycle
Start a rinse or short cycle and check that the water drains. If it still does not, the pump or control may need service.
Safety notes
- Turn off the dishwasher and, for the knockout plug step, the disposal power before working.
- Do not reach into the garbage disposal.
- Watch for broken glass in the sump; use tongs or gloves.
When should you call a pro?
- You hear humming or no sound at drain time and the filter and hoses are clear.
- The dishwasher shows a drain error code that persists after cleaning.
- Water is leaking onto the floor.
Frequently asked questions
Is a little water in the bottom of a dishwasher normal?
Some models keep a small amount of water in the sump. Water above the filter at the end of a cycle is not normal.
How often should I clean the dishwasher filter?
Check your manual. Many manufacturers suggest every month or so, more often if you do not rinse dishes.
What is a high loop?
Routing the drain hose up to the underside of the counter before it drops to the disposal or drain, which helps keep sink water from flowing back into the dishwasher.
Sources
Steps are based on these manufacturer and safety references. Your product's own manual comes first.