Is your dishwasher not draining properly? While it’s normal for there to be a bit of standing water at the bottom of your dishwasher from time to time, if you’re seeing an inch or more, it’s highly possible you have a clogged dishwasher. There’s nothing worse than opening the dishwasher and seeing dingy water pooled in the bottom. Drainage failure can mean a sink full of dirty dishes and another unnecessary chore for you to tackle. Use our guide to lean about your dishwasher and many of the most common problems and fixes.
The Quick Fix: Reset Your Dishwasher First
Before you roll up your sleeves and start dismantling anything, try the digital equivalent of “turning it off and on again.” Modern dishwashers have sensitive electronic controls that occasionally get confused, especially if the cycle was interrupted or if there was a power fluctuation.
Look for a “Cancel” or “Reset” button on your control panel and hold it down for about five seconds. Some models require you to press and hold the “Start” button instead, while others might have you press two specific buttons simultaneously. Your owner’s manual will have the exact sequence, but most dishwashers will emit a beep or show some kind of display change when the reset takes effect.
If you hear the drain pump kick on and start working after the reset, congratulations—you just saved yourself both time and money. Run a short rinse cycle to make sure everything’s working normally, then move on with your day. If you’re still looking at standing water, it’s time to dig deeper.
How do you fix a dishwasher that is not draining?
Safety First: Preparing for Hands-On Troubleshooting
Once you’ve confirmed that a simple reset won’t solve the problem, you need to prepare for some actual detective work. First things first: disconnect your dishwasher from its power source. Most dishwashers are hardwired, so you’ll need to flip the appropriate circuit breaker rather than simply unplugging it.
Remove all dishes, utensils, and dishware from both racks—you’ll need clear access to the bottom of the unit. Take out the bottom dish rack entirely; it just lifts straight up and out in most models. Now comes the unpleasant part: you need to remove that standing water.
A large measuring cup or small pitcher works well for scooping out most of the water, while towels can soak up the remainder. Yes, this water is going to be gross—it’s essentially dirty dish water that’s been sitting stagnant. Work methodically and try not to splash it around your kitchen floor.
Problem #1: Clogged Dishwasher Filter
The most common reason dishwashers stop draining properly is a clogged filter, and frankly, most people don’t even realize their dishwasher has a filter that needs regular cleaning. Located at the bottom of the unit, usually beneath the lower spray arm, this cylindrical or cup-shaped component traps food particles before they can clog up your plumbing.
To locate your filter, look for a round or square plastic piece at the very bottom of the dishwasher tub. It might be beneath the spray arm, which you can usually lift out by gently pulling upward or unscrewing counterclockwise, depending on your model. The filter itself typically unscrews or lifts out with a quarter-turn twist.
When you remove the filter, don’t be surprised if it’s absolutely disgusting. A properly functioning filter will accumulate grease, food particles, soap scum, and other debris over time. Rinse it thoroughly under hot water, using an old toothbrush to scrub away stubborn buildup. If the mesh or holes are still clogged after brushing, soak the filter in hot water with a bit of dish soap for 15-20 minutes, then scrub again.
While the filter soaks, take a look at the area where it sits. You might find additional debris that fell through—carefully remove any visible food particles, glass shards, or other foreign objects. A small cup or spoon works well for scooping out this debris.
Problem #2: Blocked Drain Screen and Sump Area
The drain screen sits around the filter area and can accumulate its own collection of troublesome debris. Look for any obvious culprits: pieces of food, labels from jars and bottles, small pieces of broken glass or plastic, and those annoying little stickers from fruits and vegetables that somehow make their way into the dishwasher.
Remove everything you can see by hand, then wipe down the entire drain screen area with a soapy sponge. Pay particular attention to the small holes or slots in the screen—these can get clogged with grease and food particles, preventing proper water flow even when the main filter is clean.
The sump area—the deepest part of the dishwasher where water collects before draining—sometimes harbors additional debris that isn’t immediately visible. Use a flashlight to get a good look at this area, and remove anything that doesn’t belong there.
Problem #3: Garbage Disposal Issues
If your dishwasher drains through your garbage disposal (and most do), a clogged disposal can completely prevent your dishwasher from draining. This connection means that when your disposal backs up, that backup affects your dishwasher too.
Run your garbage disposal for 30-60 seconds with plenty of cold water flowing. If you hear unusual grinding, rattling, or the motor sounds like it’s struggling, your disposal probably has a blockage that’s affecting your dishwasher’s drainage.
For minor disposal clogs, try running ice cubes and coarse salt through the disposal—the ice helps knock debris loose while the salt provides gentle abrasive action. Follow this with cold water and dish soap. Avoid using chemical drain cleaners in your disposal, as these can damage both the disposal and your dishwasher.
If your disposal is completely jammed and won’t turn on at all, you’ll need to manually unjam it using the hex wrench that came with the unit (usually stored beneath the disposal) or call a professional.
Problem #4: Drain Hose Complications
The drain hose carries water from your dishwasher to either your garbage disposal or directly to your kitchen sink’s drain line. Over time, this hose can develop clogs, kinks, or disconnections that prevent proper drainage.
To access the drain hose, you’ll need to pull out your dishwasher or remove the front access panel (usually held by a few screws). The drain hose is typically a ridged plastic tube about an inch in diameter. Follow it from the dishwasher to where it connects to your plumbing.
Check for obvious kinks or bends that might restrict water flow. If the hose looks fine externally, disconnect it from both ends (have towels ready—there will be water) and inspect the interior. You can run water through it or blow through it to check for blockages. If you can’t clear a blockage with water pressure or a plumbing snake, the hose will need replacement.
Problem #5: Air Gap Blockages
If you see a small chrome cylinder on your countertop or sink deck near your faucet, that’s your dishwasher’s air gap. This device prevents dirty water from flowing back into your dishwasher, but it can become clogged with food particles and debris.
Remove the chrome cap by lifting it straight up—it usually just pops off. Underneath, you’ll find a plastic cap that also lifts off, exposing the air gap’s interior tube. Use a small bottle brush or even a pencil to clear out any visible debris from this tube.
The air gap also has connections underneath your sink. You might need to disconnect and clean the hose that runs from the air gap to your garbage disposal or drain line. Look for a small hose connected to the bottom of the air gap fixture and ensure it’s not clogged or disconnected.
Problem #6: High Loop Issues
Not all dishwashers have air gaps—some use a “high loop” configuration instead. In this setup, the drain hose loops up and attaches to the underside of your countertop before dropping down to connect to your plumbing. This loop serves the same purpose as an air gap, preventing backflow.
Check under your sink to see if your dishwasher’s drain hose forms this high loop. The highest point should be at least 18 inches above the floor. If the hose has come loose and dropped down, it won’t prevent backflow properly, which can cause drainage issues.
Reattach the hose at its high point using appropriate clamps or brackets. Make sure the loop is secure and won’t drop down again with normal dishwasher vibration.
Problem #7: Internal Component Failures
If you’ve worked through all the external and easily accessible causes without success, the problem might be internal to the dishwasher itself. The drain pump, drain solenoid, or control board could be malfunctioning.
The drain pump is responsible for actively pumping water out of the dishwasher. If it’s failed, water will simply sit in the bottom of the unit. You might hear unusual noises during the drain cycle, or you might hear nothing at all when the dishwasher should be draining.
Testing these components typically requires electrical testing equipment and some technical knowledge. If you’re comfortable working with electrical components, you can test the drain pump for continuity using a multimeter. However, for most homeowners, this is where it makes sense to call a professional appliance repair technician.
Prevention: Keeping Your Dishwasher Draining Smoothly
The best way to deal with drainage problems is to prevent them in the first place. Most drainage issues develop gradually as debris accumulates over time.
Clean your dishwasher filter monthly—more often if you frequently wash very dirty dishes or if you have hard water. Scrape food scraps from dishes before loading them, but don’t pre-rinse completely (modern dishwashers and detergents are designed to handle some food soil).
Run your garbage disposal regularly with plenty of water, even if you haven’t put food waste down it. This keeps the disposal clean and ensures the drain line stays clear for your dishwasher.
Consider running an empty cleaning cycle monthly using dishwasher cleaning tablets or a homemade solution of white vinegar and baking soda. This helps remove soap scum, grease, and mineral deposits that can contribute to drainage problems.
When to Call a Professional
While many drainage issues are DIY-friendly, some situations require professional attention. Call an appliance repair technician if:
- You’ve tried all the basic troubleshooting steps without success
- You suspect electrical problems with the drain pump or control board
- Your dishwasher is still under warranty (DIY repairs might void coverage)
- You’re not comfortable working with electrical components or plumbing connections
- The problem keeps recurring despite your maintenance efforts
The Bottom Line
A dishwasher that won’t drain is frustrating, but it’s usually not a death sentence for your appliance. Most drainage problems stem from simple blockages that you can clear yourself with basic tools and a bit of patience. Work through the troubleshooting steps systematically, starting with the simplest solutions first.
Remember that regular maintenance prevents most of these problems from developing in the first place. A few minutes of monthly filter cleaning and occasional disposal maintenance will keep your dishwasher draining properly for years to come, saving you both the hassle of emergency repairs and the expense of premature replacement.
The next time you open your dishwasher to find standing water, don’t panic. Armed with this troubleshooting knowledge, you’ll be able to diagnose and fix the problem quickly, getting back to the convenience of properly functioning automatic dishwashing.
FAQ
How do I know if my dishwasher drain pump is clogged?
About five seconds after you start running a dishwasher cycle, the drain pump will start making a low humming noise. This will be due to a piece of glass blocking the impeller from turning, resulting in the dishwasher pump not working properly. When this happens, you’ll need to remove the blockage.
Is it safe to run a dishwasher with standing water?
Usually the appliance remains wet after a cycle due to the condensation drying principle which causes water droplets in the tub – they are indeed desirable here. The moisture in the air condenses on the inside walls, runs off and is pumped out.
