Dishwasher Not Draining: Safe Checks for Standing Water

Quick answer

A dishwasher not draining is most often caused by a clogged filter, a kinked drain hose, a blocked air gap, or a garbage disposal that’s full or newly installed. A little water in the bottom can be normal, but water above the filter is not. Start by checking whether the cycle finished and then cleaning the filter. This guide is for beginners dealing with standing water who want safe checks first.

Safety first

• Switch off the dishwasher before you reach into the tub. Many built-in dishwashers are wired directly, so use the circuit breaker or a switch under the sink; portable models can be unplugged.
• If you see water near an outlet, a power strip or wiring under the sink, stop. Don’t touch it. Switch off the breaker from a dry spot, or call an electrician.
• Never pour chemical drain cleaner into a dishwasher. It can damage parts and splash back on you.
• If your sink has a garbage disposal, switch it off at its wall switch before you look into it, and never put your hand inside.
• Watch for sharp knives and glass hidden in standing water.
• Don’t remove the kick plate (the panel at the bottom front) or other panels.

Before you begin

Some water that sits in the sump (the low area under the filter) is normal for many dishwashers. If water covers the filter or reaches the bottom rack, keep going.

• Did the cycle finish? A cycle interrupted by opening the door or a power blip may stop before it drains. Look at the display.
• Is the kitchen sink draining? If the sink is also slow, the clog may be in the shared drain.
• Was a garbage disposal just installed? New disposals have a knockout plug that must be removed for a dishwasher to drain into them. That’s a job for whoever installed it, or a plumber.
• Find the model number on the rating label, usually on the edge of the door or tub. The manual shows how to remove the filter and how to cancel or drain a cycle. See how to find your appliance model number and manual.

Possible causes

Things you can check yourself:

• A clogged filter at the bottom of the tub
• Food, labels or broken glass sitting in the sump area under the filter
• A drain hose kinked under the sink, often after cleaning supplies were pushed against it
• A blocked air gap (a small capped cylinder near the faucet on some sinks)
• A full or clogged garbage disposal
• A slow kitchen sink drain
• Too many suds from using hand dish soap

Problems that need a technician:

• A failed drain pump or a pump that hums but moves no water
• A blocked drain hose that can’t be cleared without taking the dishwasher out
• Control or wiring problems
• A disposal knockout plug or plumbing issue under the sink (a plumber or installer)

How to clear standing water safely

1. Try a drain or cancel. Many dishwashers drain when you cancel the cycle; how you do it varies by brand and model, so check your manual. Close the door and let it run. Did it drain? If yes, the cycle was probably interrupted. If not, go to step 2.
2. Switch off the power. Turn off the breaker or unplug the dishwasher. Leave it off for the next steps.
3. Bail out the water. If the water is hot, let it cool first. Lay towels on the floor. Remove the bottom rack. Use a cup to scoop water into a bucket, then soak up the rest with a towel. Take your time, and watch for sharp items.
4. Clean the filter. Twist out the filter as your manual shows. Rinse it under warm water and scrub gently with a soft brush. Wipe out the area where it sits, removing food, seeds, labels or bits of glass, then lock the filter back in exactly as the manual describes. Did you find a clog? If yes, restore power and run a short rinse to see if it drains. If not, go to step 5.
5. Run the garbage disposal. If the dishwasher drains through a disposal, run the disposal with cold water for a short time to clear it, then switch it off. Never put your hand in a disposal.
6. Check the air gap. If your sink has an air gap near the faucet, lift or twist off its cap and remove any gunk you can see with a paper towel. Put the cap back on firmly.
7. Look at the drain hose. With a flashlight, look under the sink for the ribbed drain hose running from the dishwasher. Move cleaning supplies and straighten any kinks you can see. Don’t disconnect the hose or pull the dishwasher out. Is it draining now? If yes, run an empty rinse to confirm. If water still sits above the filter, the blockage is likely inside the dishwasher or the plumbing.
8. Switch to the right detergent. If you saw thick foam, someone may have used hand dish soap. Bail out the suds, wipe the tub and use only automatic dishwasher detergent next time.

Picture a renter who moved a bin of sponges and sprays under the sink, flattening the drain hose. Moving the bin was the whole fix. Another family found a cherry pit wedged under the filter. If your dishes come out dirty too, see dishwasher not cleaning dishes properly. Standing water can also cause odors, covered in how to get rid of a bad dishwasher smell.

When to stop and call a qualified technician

Call a qualified appliance technician or the manufacturer’s service network if:

• The filter, air gap, disposal and hose all look clear but water still won’t drain
• You hear humming or buzzing at the drain stage with no water moving
• An error code keeps returning after you’ve followed the owner’s manual
• Water leaks onto the floor or into the cabinet
• You smell burning, see smoke or the breaker trips
• A fix would mean removing the kick plate, pulling the dishwasher out or disconnecting hoses

If the sink drain or a new disposal is the problem, a plumber or the disposal installer is the right person to contact.

FAQ

Is some water in the bottom of my dishwasher normal?

On many models, a small amount of water stays in the sump below the filter to keep seals moist. Water that covers the filter or rises toward the rack is a sign of a drain problem.

Can I use vinegar or baking soda to unclog my dishwasher?

Some people use these for cleaning, but they won’t clear a real blockage. Check your owner’s manual before adding anything, clean the filter by hand, and never use chemical drain cleaner.

Why did my dishwasher stop draining after I installed a garbage disposal?

New disposals often have a knockout plug that blocks the dishwasher inlet until it’s removed. Contact the installer or a plumber to handle it.

What is a dishwasher air gap?

An air gap is a small capped fitting near the faucet on some sinks. It keeps dirty sink water from flowing back into the dishwasher. If it clogs, water may back up or spill from it.

Can standing water damage my dishwasher?

Water left sitting can lead to odors and mold, and a blocked drain may strain the drain pump. Clear the water and the cause soon, and call a technician if it keeps happening.