Why Is My Dishwasher Not Draining? 9 Causes and Easy Fixes

A dishwasher usually does not drain because of a clogged filter, a kinked or clogged drain hose, a clogged garbage disposal or sink drain, or a blocked drain pump. The most common cause by far is a dirty filter at the bottom of the dishwasher, and it takes just a few minutes to clean.

Standing water in your dishwasher is gross, but it is one of the most fixable appliance problems. You usually need no special tools.

This guide walks you through 9 causes in order, from the easiest fix to the ones that may need a pro.

Before you start: is it really not draining?

A small puddle of clear water around the filter is normal in many dishwashers. It keeps the seals from drying out.

It is a problem if:

• There is more than an inch of water after a cycle
• The water is dirty, greasy, or smells bad
• Dishes come out dirty or covered in grit
• You see an error code about draining

Step 1: Try the drain or cancel cycle

Sometimes a cycle gets interrupted, like during a power blip or if someone opened the door, and the dishwasher never drained.

Fix: Close the door and press Cancel, Drain, or Start/Reset (the name depends on your brand). On many models, holding the button for 3 seconds starts a short drain. Wait 2 minutes and listen for the pump. Check your manual for the exact steps.

If it drains, run a short rinse cycle to make sure it keeps working.

How to remove standing water

If the drain cycle did not work, remove the water before you start fixing things.

1. Turn off the power.
2. Put towels on the floor in front of the dishwasher.
3. Pull out the bottom rack.
4. Scoop out the water with a cup or small bowl into a bucket.
5. Soak up what is left with towels or a sponge.

9 reasons your dishwasher is not draining

1. The filter is clogged

Most dishwashers made in the last 10 to 15 years have a filter at the bottom, under the lower rack. It catches food, seeds, labels, and grease. When it gets full, water cannot drain.

How to clean it:

1. Pull out the bottom rack.
2. Find the round filter in the floor of the dishwasher. It usually twists out. Turn it counterclockwise and lift.
3. Some models also have a flat mesh screen that lifts out after the round filter.
4. Rinse both parts under warm running water.
5. Scrub them gently with a soft brush and a little dish soap.
6. Wipe out the hole where the filter sits, and look for bits of glass, bones, or seeds.
7. Put the filter back and lock it in place.

Clean the filter about once a month, or more often if you do not rinse dishes before loading them.

2. The garbage disposal is clogged

In many kitchens, the dishwasher drains into the garbage disposal under the sink. If the disposal is full of food, the dishwasher water has nowhere to go.

Fix: Run cold water in the sink and turn on the garbage disposal for 20 to 30 seconds. Then run a drain cycle on the dishwasher.

3. A new disposal still has the knockout plug

If your dishwasher stopped draining right after a new garbage disposal was installed, this is very likely the cause. New disposals come with a plastic plug inside the dishwasher inlet. It must be knocked out during installation.

Fix:

1. Turn off the power to the disposal (unplug it or switch off the breaker).
2. Disconnect the dishwasher hose from the side of the disposal.
3. Put a screwdriver into the inlet and tap it with a hammer to knock out the plug.
4. Reach into the disposal (with the power off) and remove the loose plastic piece.
5. Reconnect the hose tightly.

4. The sink drain is clogged

If your dishwasher drains into the sink drain (with or without a disposal), a clogged sink will stop it from draining. If your kitchen sink is draining slowly too, this is likely the problem.

Fix: Clear the sink drain with a plunger, a drain snake, or by cleaning the P-trap under the sink. Avoid chemical drain cleaners, which can damage pipes and the dishwasher.

5. The drain hose is kinked or clogged

The drain hose is a ribbed plastic hose that runs from the dishwasher to the sink drain or disposal. If it is bent, crushed, or clogged with food and grease, water cannot flow out.

How to check:

1. Turn off the power and water to the dishwasher.
2. Look under the sink at the hose. Make sure it is not kinked or pinched.
3. Remove the kick plate at the bottom front of the dishwasher to see the hose where it leaves the dishwasher.
4. If you can, disconnect the hose from the sink end and hold it over a bucket. Blow through it or run water through it to see if it is clogged.
5. Clear a clog with a long, flexible brush, or replace the hose if it is damaged.

Tip: The drain hose should rise up in a high loop under the sink, fastened near the underside of the counter, or connect to an air gap. This stops dirty sink water from flowing back into the dishwasher.

6. The air gap is clogged

Some kitchens have an air gap. It is a small metal or plastic cap on the sink or countertop, next to the faucet. It stops dirty water from flowing back into the dishwasher. If it gets clogged, water may spill out of it or the dishwasher may not drain.

Fix: Twist or pull off the cap, remove the inner cover, and clean out any gunk with a small brush or pipe cleaner. Rinse it and put it back.

7. The drain pump is blocked

The drain pump pushes water out of the dishwasher. Broken glass, fruit pits, bones, and other hard pieces can get stuck in it.

How to check:

1. Turn off the power.
2. Remove the filter.
3. Look in the sump area below the filter. On many models, there is a small cover you can remove to reach the pump.
4. Remove any objects carefully. Wear gloves, since there may be broken glass.

If you hear a humming sound during the drain cycle but no water moves, the pump may be jammed or broken. If you hear nothing at all, the pump motor may have failed. A broken pump usually needs a repair technician.

8. The check valve is stuck

Some dishwashers have a small check valve that lets water leave but stops it from coming back. If it gets stuck closed, water cannot drain.

Fix: Look up where the check valve is on your model. It is often near the pump or where the drain hose connects. Clean it or free it if it is stuck. If you are not sure, let a technician check it.

9. The control board or sensors have failed

Sometimes the dishwasher's control board or a sensor fails, and it never tells the pump to run. You may see an error code.

Fix: Look up the error code in your manual or on the maker's website. Try resetting the dishwasher by turning off the power at the breaker for 5 minutes. If the problem continues, call a repair technician.

Quick reference table

How to keep your dishwasher draining well

• Scrape food off dishes before loading. You do not need to rinse them fully.
• Clean the filter once a month.
• Run the garbage disposal before you start the dishwasher.
• Run hot water in the sink for a few seconds before starting a cycle, so the dishwasher fills with hot water right away.
• Use the right detergent and the right amount. Too much can leave residue.
• Run an empty hot cycle with a dishwasher cleaner once a month.
• Keep the drain hose in a high loop under the sink.

Why does my dishwasher smell bad?

A dishwasher that does not drain well often starts to smell. Food and water sitting in the bottom grow bacteria. Cleaning the filter usually fixes the smell. If your sink or whole kitchen smells like a sewer, the problem may be the drain line. Our guide on finding the cause of a sewer smell at home can help.

When to call a repair technician

Call a technician if:

• The filter, hose, air gap, and sink drain are all clear but it still will not drain
• You hear humming or no sound at all during the drain cycle
• You see an error code that does not clear
• Water is leaking onto the floor
• You are not comfortable taking off panels or hoses

Have the model number ready. It is usually on a sticker on the edge of the door or the side of the tub.

The bottom line

When your dishwasher will not drain, start with the easy fixes. Run a cancel or drain cycle, then clean the filter at the bottom of the tub. Run the garbage disposal, clear the sink drain, and check that the drain hose is not kinked. If you just installed a new disposal, knock out the plug. If it still will not drain, the pump or control board may need a repair technician.