My Dishwasher Won’t Drain – Causes and Fixes

Whether you’ve noticed water pooling inside your dishwasher or have noticed an unpleasant smell, a dishwasher that won’t drain is a fairly common plumbing issue.

In some cases, there are simple fixes you can try if your dishwasher won’t drain.

Here, we’ll cover the possible causes behind your dishwasher not draining and what to do to fix it.

Reasons Your Dishwasher Won’t Drain

Although it is normal for some dishwasher brands to retain a small amount of water in the bottom at the end of a cycle, excess water is an issue.

If your dishwasher won’t drain, there are a variety of potential causes. Here are some of the most common reasons that lead to a dishwasher not draining.


Damaged Drain Pump

A drain pump can become clogged or blocked by leftover built-up grease and food debris, preventing water from draining. If the drain pump is blocked, you may notice an odd noise as the pump struggles to drain the water.


Dirty Filters

If you’ve noticed your dishwasher won’t drain, check the filters. If soggy food debris or grease is built up within the filter, it can become blocked and prevent water from draining properly.


A Blocked Sink or Drain Hose

A dishwasher’s drain hose works to transport dirty water out of the appliance. It is typically connected to the kitchen sink’s drain line. If the drain hose is blocked, dirty water won’t be able to drain properly.

A blocked kitchen sink drain can also pose a problem. If a drain snake does not unblock the drain, call a plumber for help.


10 Steps to Try If Your Dishwasher Won’t Drain

Here are 10 simple techniques to try if your dishwasher won’t drain. Before performing any troubleshooting, be sure to cut power to the dishwasher and isolate the water supply.


1. Listen to Your Dishwasher

Before you cut power to your dishwasher, run a cycle and pay attention to the sounds it makes. Does it sound different than normal? Is it making an odd clicking noise or a new humming sound? Odd noises may indicate a motor or drain pump that needs professional replacement.


2. Remove Any Standing Water

If you need to remove standing water from your dishwasher, here are steps on how to drain a dishwasher properly:

  • Place newspaper or towels under and around the dishwasher’s base
  • Slide out the bottom dish rack so it is out of the way
  • Dispose of any pooled water by scooping it out with a small cup and dumping it into a bucket
  • Once most of the pooled water is gone, clean up the rest with towels


3. Check the Filter for Debris

The filter can become clogged with debris and prevent a dishwasher from draining properly. You can check the owner’s manual to locate the filter, although it is most likely at the bottom of the dishwasher under the lower spray arm.

Clear away any food particles, foreign objects, or debris you find. You can typically remove the filter from the dishwasher by twisting the filter according to the arrows.

Once removed, you can get a better look at the filter — and the sump below — by lifting the mesh filter plate. Check for any food debris or blockages and remove them immediately.

To clean the filter, run it under water to loosen debris and build-up. You may want to consider a soapy toothbrush for scrubbing areas with extra build-up. Once clean, replace the filter and see if your dishwasher draining problem is solved.

4. Check for a Blockage

Do you see any food debris or foreign items on the bottom of the dishwasher? Check near the bottom rear of the dishwasher to make sure nothing is causing a blockage.

Remove any debris, food particles, paper bits, or objects you find.


5. Check the Dishwasher Door Latch

Sometimes if your dishwasher won’t drain, it can be as simple as a door that isn’t latched properly. An unlatched door will prevent your dishwasher from draining properly.

Double-check that the door is fully latched and run a cycle to see if it drains properly this time. If the latch won’t close properly, it’s likely time for a replacement latch.


6. Check the Garbage Disposal

A full garbage disposal can lead to a dishwasher that won’t drain. Take out the drain plug and try running the garbage disposal for 30 seconds. Sometimes this is enough to repair clogging and get your dishwasher draining properly again.

Note: Never put your hands down the garbage disposal.


7. Check the Drain Hose

The drain hose is usually found underneath the sink in between the drain line and the drain pump. Follow these steps to make sure it is operating properly:

  • If you notice any kinks in the drain hose, carefully straighten them
  • If you notice or suspect blockages, remove the hose by loosening the clamps that secure it in place
  • Blow into one end of the hose to try to dislodge any blockages (you can also straighten out a wire hanger and poke that through the hose to try and clear any debris)
  • Make sure the drain hose seal is tight

If none of these steps helps solve the problem — or if you aren’t comfortable handling DIY repairs — reach out to our team of experts and we’d be happy to help.


8. Clean the Air Gap

The air gap is a less common cause of a dishwasher that won’t drain, but it is still worth checking. Depending on the building codes in your area, your dishwasher may or may not be required to have an air gap.

Check the air gap, the tiny cylinder at the back of the kitchen sink, to make sure no water is coming out of it when you run the dishwasher.

If you notice water coming out of the air gap during a wash cycle, it most likely indicates a blockage between the garbage disposer and the air gap.

To unblock it, remove the cap (twist it counterclockwise to take it off) from the air gap and use a stiff brush and a mixture of water and baking soda to clean it.


9. Check the Drain Valve

A drain valve’s function involves opening the solenoid, a part that allows water to drain out properly during the wash cycle. Not all dishwashers have drain valves, so you’ll want to check the owner’s manual to see if your dishwasher does.

You can test the drain valve by pushing on the valve bracket and making sure it isn’t stuck. If the valve does not move without resistance, you likely need to replace the drain valve.


10. Try Vinegar and Baking Soda

If you’re looking for a quick tip on how to unblock a dishwasher, consider using this DIY fix featuring vinegar and baking soda:

  • Mix one cup of vinegar and one cup of water
  • Pour the mixture into the standing water
  • Let the mixture sit for about 20 minutes
  • Rinsing with hot water
  • Run the rinse cycle after this and see if it loosens any clogs

Tips to Keep Your Dishwasher Draining Correctly

Here are some preventative measures to keep your dishwasher draining properly:

  • Use a dishwashing detergent recommended by the manufacturer.
  • Clean your dishwasher filters once a fortnight (check the owner’s manual to local the filter and get instructions on how to clean it properly)
  • Have your dishwasher professionally serviced on an annual basis to ensure all the parts are working properly
  • Clean excess food debris off of plates and utensils before placing them in the dishwasher
  • Do not use drain cleaners in the dishwasher (their caustic ingredients may damage components in the dishwasher)
  • Use the proper amount of dishwasher detergent
  • Address any problems quickly before they lead to expensive repairs or damage
  • Load the dishwasher correctly according to the manufacturer’s instructions


Did You Perform the Steps But Your Dishwasher Still Won’t Drain?

If your dishwasher won’t drain even after following the steps above, it’s time to call in a professional plumber. It is important to get the draining issues evaluated before you wind up with water damage or extensive repairs.

Not comfortable with DIY fixes? We’re happy to help. There is no job too big or too small and we understand that not everyone is comfortable troubleshooting or trying to perform dishwasher repairs on their own.

Our licensed plumbing technicians can assess your drain issue, pinpoint the problem, and provide a prompt solution. You can also check to see if your dishwasher is still under warranty and contact the manufacturer directly for assistance.

If you have questions about a dishwasher not draining or want one of our expert plumbers to come to evaluate your dishwasher, please do not hesitate to contact us.