My Dishwasher Won’t Drain. Now What?

Craig Plumbing Blog Posts-dishwasherdrain

You load up your dishwasher with dirty dishes, turn it on, and wait for the cycle to finish. But when you come back to unload, you find that the water hasn't drained! Now, you're stuck with a sink full of dirty dishes and a dishwasher full of dirty water. What gives?

If your dishwasher won't drain, don't panic! This is a relatively common problem that can sometimes be fixed without calling a professional.

In this blog post, we'll explain what could be causing your dishwasher to fail to drain properly and give you some tips on how to fix the problem. Read on to learn more!

Possible Causes of a Dishwasher Not Draining Properly

There are several possible reasons why your dishwasher might not be draining properly. It could be a simple clog in the drain line or a more serious problem with the pump or motor. Let's take a look at some of the most common causes of dishwasher drainage problems:


Clogged Drain Pipe: Another common reason for dishwasher drainage problems is a clogged drain hose. The drain hose connects the dishwasher to the drain under your kitchen sink. Over time, food particles and grease can build up in the drain line, causing it to become blocked.

If this hose becomes clogged, it can prevent water from draining properly. If your dishwasher is not draining properly, check the drain line for any signs of blockage.

To clean the drain hose, disconnect it from both the dishwasher and the sink and then flush it out with hot water. If you have a wire hanger handy, you can also use it to clear any debris that may be stuck in the hose. Once you've flushed out the hose, reattach it to both the dishwasher and sink and turn on the dishwasher to see if the problem has been resolved.


Clogged Sink Trap: Another common reason for a dishwasher not draining is a clogged sink trap. The sink trap is located beneath the sink and is responsible for catching debris before it has a chance to enter the dishwasher. Over time, the sink trap can become clogged with food particles, grease, and soap scum, which can prevent water from draining properly.

To clean the sink trap, simply remove it (you may need a pliers or adjustable wrench) and empty it into the garbage. Once the sink trap is clear, run some hot water through it to make sure it's clear before replacing it.


Defective Pump or Motor: If your dishwasher still isn't draining properly after trying these two fixes, there's a good chance that there's something wrong with your dishwasher's pump. The pump is responsible for circulating water and moving it through the drainage system.

If there's something blocking the pump or if the pump itself is damaged, it can prevent water from draining properly. To check for blockages, remove any items that may be blocking access to the pump (such as dishes or detergent bottles) and then take a look inside. Remove anything that may be preventing the pump from working properly.

If you don't see anything blocking the pump, it's possible that the pump itself is damaged and it may not be able to spin the impeller (the blades that push water through the pump) fast enough to generate enough pressure.

If you think that your dishwasher's pump or motor may be damaged, call a professional for help.


Air Gap Issues: In some cases, dishwashers may not drain properly because of air gap issues. The air gap is a small hole located on the back of the dishwasher that allows air into the dishwasher as it drains water. If this hole becomes blocked, water will back up into the dishwasher.

If your air gap is blocked or defective, dirty water may be siphoned back into your home's drinking water supply instead of being discharged through the drain line.

To check for air gap issues, take a look at the discharge tube (the tube that carries water from the air gap to the drain) and make sure that there is no debris blocking it. To clean the air gap, unplug the dishwasher and use a straightened wire hanger to clear any debris from the hole.



A dishwasher that doesn't drain properly is certainly frustrating, but fortunately, these are a few things you can try before calling a professional appliance repair service.

If none of those solutions work, then you may have a more serious problem which will require professional help to fix. So give us a call today! We're always happy to help!