How to Unclog a Dishwasher Drain in 5 Steps | Whirlpool (2024)

How can you tell if your dishwasher is clogged? If it’s not draining very well or if an inch or more of standing water consistently collects in the bottom of the tub, you likely have a clogged dishwasher. With all of the little worries of the day, the last thing you need is a malfunctioning, smelly dishwasher. Who has the time or the flexibility to wait for a visit from a service technician for a dishwasher that doesn't clean your dishes?

Luckily, there’s some troubleshooting you can do to unclog the dishwasher before calling in a professional.

Select a topic below to start troubleshooting your clogged dishwasher.

Why is there water in the bottom of your dishwasher?

There are a few reasons why your dishwasher won’t drain. The most common source of clogs comes from a blockage in the dishwasher's filter. Or, you may have an issue with your dishwasher’s air gap, drain valve, drain hose or even your garbage disposal, causing your dishwasher to clog.

Locate the filter

To find the filter assembly, remove the bottom dish rack and look in the bottom of the tub. In some models, the assembly is located in a back corner, while in others it’s somewhere near the base of the spray arm.

Remove the filter

The filter is often covered by a cage or grille. You can typically remove the dishwasher filter by hand, but some require a screwdriver.

Once the covering is out of the way, you can pull out the filter. If yours is clogged, you’ll probably see food particles, soil or other visible debris caught in the fine mesh.

Rinse and replace it

You can rinse most of the soils away by simply running the filter under the sink faucet. Scrub caked-on debris away with a soft brush, like an old toothbrush. But don’t use anything made of a tough or abrasive material because you might damage the filter.

Replace the now sparkling clean filter when you’re done and fit the cage or grille securely back in place.

Check inside the drain pump

Sometimes glass can break while in the dishwasher which can lead to small solid debris getting into the drain pump outlet. Remove the drain pump and vacuum out the area to remove debris. Then, replace the drain pump.

Check the garbage disposal

Built-in dishwashers typically drain via the garbage disposal so if your dishwasher is still clogged, this may be the culprit. Turn on your garbage disposal to clear away any leftover food. If you hear a loud sound after turning on your garbage disposal, it may mean your garbage disposal is clogged and you’ll need to troubleshoot that as well.

Have you recently installed or serviced your garbage disposal? Check to see if the knockout drain on the dishwasher was removed. This sometimes neglected step is a common misdiagnosis of a clogged dishwasher.

Clean the sink’s air gap

A dishwasher’s air gap lets air into the dishwasher so it can properly drain without creating a vacuum. Located on the top of the sink, it doesn’t allow anything except for air to come through. However, this air gap may become clogged or blocked and can cause drainage problems in your dishwasher. If you notice any buildup in the sink’s air gap, clean it out and make sure it's tightly secured.

Clean the drain hose

Check your drain hose to make sure it is properly secured to the sink or garbage disposal. The drain hose connects the dishwasher to your garbage disposal or sink and is either located under the sink or behind the dishwasher. If it is properly connected, make sure it is cleared of food or debris. You can clean your drain hose using a drain cleaner solution or you can make your own. Baking soda and vinegar is commonly used as a natural drain cleaner and can be a great solution for weaker clogs. However, you may want to use a stronger drain cleaner for clogs that need to be dissolved right away.

Have you recently redone your kitchen plumbing? An improperly installed drain hose during a remodel is a common cause for the dishwasher not draining. Drain hoses can kink during an installation and can cause the pump to not drain. Sometimes a drain hose has a built-in check valve for one way flow and is installed backward. If the dishwasher was self installed, make sure to follow the recommendation to replace the drain hose. An old drain hose can build up drain sentiments and restricts flow.

How can you prevent dishwasher clogs?

Make sure your dishwasher is cleaned and regularly maintained to help prevent dishwasher clogs. This includes, but is not limited to:

• Removing crumbs and leftover food from dishes before loading the dishwasher.

• Choosing a hot water cycle on the dishwasher.

• Wiping down the exterior and interior of the dishwasher and any other parts you can access.

• Regularly checking and cleaning the dishwasher filter.

• Running the dishwasher often and always using dishwasher detergent.

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