Opening your dishwasher to find a pool of dirty water sitting at the bottom is never a good sign. A dishwasher that won’t drain properly isn’t just frustrating—it can also lead to bad odors, water damage, and costly repairs if ignored too long.
The good news? Many of the most common causes behind a dishwasher that won’t drain are fixable with a little DIY effort.
In this post, we’ll walk you through 5 common reasons your dishwasher won’t drain—and exactly how to fix them. Plus, we’ll share when it’s time to call a professional appliance repair technician.
1. Clogged Dishwasher Filter
One of the most common culprits is also one of the easiest to fix.
What’s happening:
Food particles, grease, and debris build up in the filter, which prevents water from draining properly.
Signs to look for:
- Standing water in the bottom of the dishwasher
- Slow draining
- Foul odors
How to fix it:
- Remove the bottom dish rack to access the filter.
- Twist or lift out the filter (check your user manual if needed).
- Rinse the filter under warm water. Use a soft brush or sponge if needed.
- Replace the filter and run a short cycle to test drainage.
🛠 Pro tip: Clean your dishwasher filter once a month to prevent buildup.
2. Blocked Drain Hose
The drain hose carries water from your dishwasher to the sink drain or garbage disposal. If it’s kinked or clogged, water won’t drain.
What’s happening:
Food debris, grease, or even small items can block the hose.
How to check & fix:
- Unplug the dishwasher and turn off the water supply.
- Locate the drain hose (usually at the back or underneath the unit).
- Detach the hose and inspect for blockages or kinks.
- Clear any clogs using a wire hanger or a plumber’s snake.
- Reattach the hose securely and run a test cycle.
🛑 Safety tip: Always lay down a towel or shallow pan—some water may spill out when you disconnect the hose.
3. Faulty Drain Pump
The drain pump uses an impeller to push water through the hose. If the pump fails, your dishwasher won’t drain no matter how clean the filter is.
Signs of a failing pump:
- Humming noise without draining
- Water remains despite clear filter and hose
- Error codes on digital displays (check your model’s manual)
How to fix:
- Test the pump with a multimeter (if you’re comfortable with electrical work).
- Look for signs of damage or blockages in the pump housing.
- Replace the pump if it’s burned out or damaged.
📞 Tip: If you’re not confident with electrical parts, this is a great time to call a qualified appliance repair technician.
4. Garbage Disposal Connection Issue
If your dishwasher is connected to a garbage disposal, the issue might not be in the dishwasher at all.
What’s going wrong:
If the knockout plug inside the disposal wasn’t removed during installation, the water has nowhere to go.
How to fix:
- Turn off power to the disposal.
- Disconnect the drain hose and inspect the connection.
- Use a screwdriver to knock out the plug (it’s a small plastic disk inside the disposal’s inlet).
- Reconnect everything securely and test the drain cycle.
5. Broken or Stuck Check Valve
The check valve prevents dirty water from flowing back into your dishwasher after it drains. If it’s broken or stuck open, you may see backflow and standing water.
How to identify & fix:
- Locate the check valve near the drain pump or hose connection.
- Remove and inspect it—look for debris or damage.
- Clean or replace it if needed.
🧰 Replacement parts are typically inexpensive and can be found at most appliance parts stores or online.
When to Call a Professional Appliance Repair Technician
If you’ve tried the above steps and your dishwasher still won’t drain, it might be time to bring in the pros. You could be dealing with:
- A burned-out motor
- Electrical issues
- Control board failure
- Internal clogs in hard-to-reach areas
👨🔧 A certified technician can diagnose and repair these issues safely and efficiently—saving you time, frustration, and the risk of damaging your appliance further.
Need help now? Contact our expert appliance repair team here.
Prevent Future Drainage Problems
- Clean your filter monthly
- Rinse off large food scraps before loading dishes
- Avoid overloading the racks
- Run hot water in the sink before starting the dishwasher to help dissolve grease
- Schedule regular appliance check-ups
Conclusion
A dishwasher that won’t drain doesn’t always mean disaster. In many cases, a quick clean or a simple hose check is all it takes. Now that you know the top 5 causes—and how to fix them—you’re better prepared to tackle the problem head-on.
You can also read more about how to load a dishwasher for maximum efficiency here.
Still stuck? Our team of appliance repair pros is just a call away.
Contact our expert team at C&W Appliance Services for all dishwasher repair and other appliance repair and maintenance services. Serving Dallas / Fort Worth, Highland Park, University Park, Southlake, and beyond, we’re here to ensure your appliance runs efficiently for years to come
