Dishwasher Not Draining: Causes and Step-by-Step Checks
Quick Answer
If your dishwasher is not draining, common causes include a clogged filter, food debris in the bottom of the dishwasher, a kinked drain hose, a blocked garbage disposal connection, or a malfunctioning drain pump.
Before assuming an electrical or mechanical component has failed, start with these simple checks:
Make sure the wash cycle finished normally and was not interrupted.
Check whether an unusual amount of water remains in the bottom of the tub.
Clean the removable dishwasher filter according to the owner's manual.
Look for visible food debris near the drain.
Check whether the kitchen sink drains normally.
Inspect accessible sections of the drain hose for kinks.
If the dishwasher connects to a garbage disposal, check for drainage problems at the sink.
If these checks do not resolve the issue, a drain pump blockage or malfunction may need professional attention.
Important: A small amount of water around the filter or sump may be normal on certain dishwasher models.
However, standing water covering the tub floor after a completed cycle, persistent odors, dirty water returning to the dishwasher, or unusual draining noises may indicate a problem.
Before removing filters or handling debris, stop the cycle and follow the manufacturer's instructions for safely disconnecting power.
Do not perform electrical tests or remove technical service panels.
In this guide
How Does a Dishwasher Drain?
During a wash cycle, the dishwasher uses water to clean and rinse dishes.
At specific points in the cycle, that water must be removed from the tub.
On many models, the drainage system includes:
- Dishwasher filter: Traps food particles and other debris.
- Sump: Collects water at the bottom of the dishwasher.
- Drain pump: Moves wastewater out of the appliance.
- Drain hose: Carries wastewater to the household drainage system.
- Sink drain or garbage disposal connection: Allows dishwasher wastewater to enter the household drain.
- Air gap or high loop: Installation features designed to help prevent wastewater from flowing back into the dishwasher, depending on the installation and local requirements.
- Electronic controls: Determine when the drain pump should operate.
If water cannot move through this system properly, it may remain inside the dishwasher.
However, standing water does not automatically mean the drain pump is defective.
A clogged filter, blocked drain hose, or plumbing problem can produce similar symptoms.
Is It Normal to Have Water in the Bottom of a Dishwasher?
It depends on the amount of water and the dishwasher model.
Some dishwashers retain a small amount of water inside the sump or filter area as part of their normal design.
This may help protect certain internal seals.
However, a significant amount of standing water covering the bottom of the tub after a completed cycle requires investigation.
| Situation | What It May Mean | Recommended Next Step |
|---|---|---|
| Small amount of water inside the sump or filter area | May be normal on certain models | Check the owner's manual |
| Water covering much of the tub floor | Possible drainage problem | Inspect the filter and accessible drain area |
| Water remaining after an interrupted cycle | Drain phase may not have completed | Check the cycle and Cancel/Drain function |
| Dirty water returning after the cycle | Possible backflow or household drainage issue | Check the sink, drain hose, and connections |
| Standing water with an error code | The dishwasher may have detected a problem | Look up the code in the model's manual |
There is no universal amount of residual water that applies to every dishwasher.
Most Common Causes of a Dishwasher Not Draining
| Possible Cause | Common Symptom | First Check | Possible Solution |
|---|---|---|---|
| Interrupted cycle | Water remains after cancellation or interruption | Cycle status | Use Cancel/Drain according to the manual |
| Clogged filter | Slow or incomplete drainage | Removable dishwasher filter | Clean the filter |
| Debris in the sump | Slow draining or unusual noises | Visible debris in accessible areas | Remove safely according to the manual |
| Kinked drain hose | Water cannot flow out properly | Accessible hose sections | Correct positioning if permitted |
| Clogged drain hose | Partial or complete drainage failure | Signs of blockage | Professional cleaning or replacement |
| Clogged sink drain | Sink and dishwasher drain poorly | Sink drainage | Address the household plumbing blockage |
| Blocked garbage disposal connection | Water cannot drain into the disposer | Sink and disposer operation | Manufacturer-approved cleaning or service |
| Garbage disposal knockout plug still installed | Newly installed dishwasher does not drain | Recent garbage disposal installation | Correct the installation |
| Clogged air gap | Water backs up or escapes near the sink fitting | Accessible air gap components | Clean according to manufacturer instructions |
| Improper drain hose installation | Wastewater flows back into the dishwasher | High loop, air gap, and hose routing | Correct installation |
| Blocked drain pump | Buzzing or humming without proper drainage | Filter and approved pump access | Manufacturer-approved cleaning or service |
| Failed drain pump | Persistent drainage failure | Symptoms after basic checks | Professional diagnosis and replacement |
| Electrical or control problem | Drain cycle does not activate | Error code and operating behavior | Professional diagnosis |
These symptoms suggest possible causes but do not confirm a specific component failure.
What to Check First
Make Sure the Cycle Actually Finished
Before investigating internal components, check whether the dishwasher completed its program.
Drainage may not have occurred because:
- The door was opened during the cycle.
- The program was interrupted.
- A power outage occurred.
- A cancellation sequence did not finish.
- An error message appeared.
Some dishwashers offer a Cancel/Drain feature that activates the drain pump.
The procedure varies by manufacturer.
Consult the owner's manual before using it.
Check How Much Water Remains
Open the dishwasher only when it has stopped and is safe to access.
Determine whether water is limited to the filter area or is covering a large portion of the tub floor.
Do not touch standing water immediately after a hot wash or rinse cycle.
Check the Kitchen Sink
Many dishwashers drain through the plumbing beneath the kitchen sink.
If the sink is clogged or draining slowly, dishwasher wastewater may have difficulty reaching the household drain.
Check whether the sink drains normally.
Do not pour chemical drain cleaners into the dishwasher.
Inspect the Filter
On models with removable filters, accumulated food particles can interfere with water flow.
Cleaning the filter is one of the first troubleshooting steps recommended by many manufacturers.
Consider Recent Changes
Ask yourself:
- Was the dishwasher recently installed?
- Was the garbage disposal replaced?
- Was plumbing work performed under the sink?
- Was the drain hose moved?
- Was the filter recently removed and reinstalled?
Recent installation or maintenance work can provide useful clues.
Step-by-Step Dishwasher Troubleshooting
Step 1: Stop the Dishwasher Safely
If the dishwasher is running, use the manufacturer's recommended cancel or stop procedure.
If available, try the Cancel/Drain function before beginning maintenance.
Allow the machine to stop completely and let hot water cool.
Before removing filters or working around the drain area, disconnect electrical power as directed by the owner's manual.
For hardwired dishwashers, this may involve switching off the correct circuit breaker.
If the work involves water connections, shut off the water supply when required.
Do not assume that pressing the Power button fully disconnects electrical power.
Step 2: Remove Standing Water if Necessary
If standing water prevents access to the filter, carefully remove it.
Depending on the model, you may use:
- A small container or cup.
- A sponge.
- Absorbent towels.
Keep water away from electrical outlets and connections.
Do not tilt or move the dishwasher to empty it.
If you notice smoke, a burning smell, or another electrical warning sign, stop troubleshooting and seek professional assistance.
Step 3: Remove and Clean the Filter
Locate the filter at the bottom of the dishwasher tub.
Removal procedures vary.
Some models have a filter assembly that must be rotated to unlock it.
Others use different filter systems, including designs not intended for routine homeowner removal.
If the manufacturer allows filter removal:
- Remove the lower dish rack.
- Locate the filter assembly.
- Unlock it according to the manual.
- Carefully remove the filter.
- Rinse it under running water.
- Use a soft brush and mild dish soap if recommended.
- Remove debris without damaging the filter mesh.
- Reinstall and lock the filter correctly.
Avoid wire brushes and abrasive cleaning tools.
An improperly installed filter can affect cleaning performance and allow debris to enter areas where it does not belong.
Step 4: Check for Visible Debris
With the filter removed, if permitted by the manufacturer, inspect the accessible sump area.
Possible obstructions include:
- Food scraps.
- Packaging labels.
- Seeds.
- Small bones.
- Toothpicks.
- Broken glass.
- Other foreign objects.
Use a flashlight to inspect the area.
Do not place your fingers into unfamiliar openings.
Broken glass may be difficult to see.
If sharp objects are present, follow the manufacturer's instructions for safe removal. Do not attempt to retrieve objects lodged deep inside the machine.
Step 5: Check the Kitchen Sink Drain
Make sure the kitchen sink drains normally.
If household plumbing is blocked, dishwasher wastewater may be unable to flow into the drain.
If water backs up or the sink has a significant clog, contact a plumber.
Step 6: Check the Garbage Disposal
If the dishwasher drains through a garbage disposal, check whether the disposal or sink drainage system appears obstructed.
Use the garbage disposal only according to its manufacturer's instructions and only when it is safe to operate.
Never put your hands inside a garbage disposal.
If the disposal is jammed, makes unusual noises, leaks, or has an electrical problem, stop using it and seek appropriate service.
Step 7: Inspect the Drain Hose
The dishwasher drain hose carries wastewater to the household drainage system.
Check only accessible sections, usually beneath the kitchen sink.
Look for:
- Sharp bends or kinks.
- Crushed tubing.
- Objects pressing against the hose.
- Visible leaks.
- Recent changes to the installation.
Do not pull the dishwasher out of its cabinet simply to reach hidden hoses.
Avoid disconnecting plumbing connections or removing internal panels without appropriate training.
Step 8: Check the High Loop or Air Gap
Depending on the installation, the dishwasher may use a high loop, an air gap, or another arrangement specified by the manufacturer and local plumbing code.
These features help prevent wastewater from flowing back into the dishwasher.
Check whether the accessible installation matches the owner's manual.
Do not reroute the drain hose without understanding the manufacturer's requirements and applicable local codes.
Step 9: Consider the Garbage Disposal Connection
If the dishwasher or garbage disposal was recently installed, the drain connection may not have been prepared correctly.
One common installation issue is a knockout plug left inside the garbage disposal's dishwasher inlet.
The plug blocks the connection until it is removed during installation.
If it remains in place, dishwasher wastewater cannot pass through that inlet.
Confirming and correcting this problem usually requires disconnecting the drain hose.
For safety, have a qualified installer or technician perform that work if you are not trained to do so.
Step 10: Consider the Drain Pump
If the filter, sink, accessible hose sections, and installation checks appear normal, but water still does not drain, the pump may require attention.
Possible causes include:
- Debris obstructing the pump area.
- A foreign object caught in the mechanism.
- An incorrectly seated pump cover on applicable models.
- A defective pump motor.
- An electrical control problem.
Access procedures vary significantly by model.
Do not perform electrical tests or attempt to turn the pump impeller by hand unless the manufacturer explicitly provides a safe homeowner procedure.
Step 11: Perform a Safe Drain Test
After properly reinstalling all user-removable components:
- Confirm the filter is locked into place.
- Reinstall the lower dish rack.
- Close the dishwasher door.
- Restore electrical power only if there are no leaks or electrical hazards.
- Run the manufacturer-recommended drain or rinse cycle.
- Check whether the water drains normally.
Do not repeatedly run cycles if significant standing water, sewage backflow, or a suspected leak remains.
If the problem continues, contact an appliance technician.
Dishwasher Not Draining: Troubleshooting Decision Tree
Use this decision sequence to narrow down the problem.
Decision 1: Did the Dishwasher Complete Its Cycle?
No.
Check for an interrupted program, power outage, or cancellation.
Follow the manufacturer's instructions for restarting or draining the dishwasher.
Yes.
Continue to Decision 2.
Decision 2: Is There an Unusual Amount of Standing Water?
No.
A small amount of residual water in the sump may be normal.
Check the owner's manual.
Yes.
Continue to Decision 3.
Decision 3: Is the Dishwasher Filter Clogged?
Yes.
Clean and reinstall the filter according to the manual.
Then check whether drainage returns to normal.
No.
Continue to Decision 4.
Decision 4: Is the Sink or Garbage Disposal Clogged?
Yes.
The problem may be in the kitchen's drainage system.
Address the blockage safely or contact a plumber.
No.
Continue to Decision 5.
Decision 5: Is There a Visible Drain Hose Kink or Installation Problem?
Yes.
Consult the installation instructions and arrange correction if necessary.
No.
Continue to Decision 6.
Decision 6: Did the Problem Start After Installation?
Yes.
Ask the installer to check the garbage disposal connection, knockout plug, and drain hose routing.
No, or the cause is unclear.
Continue to Decision 7.
Decision 7: Is the Dishwasher Still Not Draining?
Yes.
An inaccessible blockage, drain pump malfunction, electronic control issue, or another internal problem may be responsible.
Next step: Arrange professional appliance service.
Why the Dishwasher Filter Matters
The dishwasher filter prevents larger food particles from circulating freely through the washing system.
When debris accumulates, water flow may become restricted.
Possible symptoms include:
- Slow draining.
- Standing water after a cycle.
- Persistent odors.
- Food particles remaining on dishes.
- Reduced cleaning performance.
Cleaning frequency depends on the dishwasher model and usage.
Some dishwashers have removable filters that require routine maintenance.
Others use different filtration systems or self-cleaning mechanisms.
Always follow the instructions for your model.
Can I Use Drain Cleaner on the Filter?
No.
Do not use chemical sink drain cleaners inside the dishwasher.
These products may damage components and create chemical exposure hazards.
Use only cleaning products and procedures approved by the manufacturer.
Dishwasher Drain Hose Problems
The drain hose may develop problems involving blockage, positioning, or installation.
Kinked Drain Hose
A sharp bend can restrict water flow.
This may happen after moving the appliance or storing items beneath the kitchen sink.
Clogged Drain Hose
Food particles, grease, and other debris can accumulate inside the hose.
If the blockage is inaccessible, clearing it may require professional plumbing work or hose replacement.
Improper Drain Hose Installation
Incorrect hose routing can allow wastewater from the sink to flow back into the dishwasher.
Installation instructions specify the appropriate hose arrangement.
What Is a Dishwasher High Loop?
A high loop is a drain hose configuration in which the hose rises to an elevated point before connecting to the household drain.
When properly installed and permitted, it helps reduce the risk of wastewater flowing backward.
What Is a Dishwasher Air Gap?
An air gap is a plumbing device commonly installed on or near the kitchen sink.
It provides a physical air separation in the drainage path to help protect against wastewater backflow.
Some U.S. jurisdictions require an air gap.
A high loop is not automatically an acceptable substitute for an air gap when local plumbing code requires one.
Do not modify the installation without checking the dishwasher manual and local plumbing requirements.
How Can a Garbage Disposal Prevent Dishwasher Drainage?
In the United States, many dishwashers drain through the kitchen sink's garbage disposal, also called a garbage disposer.
If the disposal or its drain connection becomes blocked, dishwasher wastewater may not drain properly.
Possible Problems
- Food debris accumulating in the garbage disposal.
- A clogged sink drain.
- A blocked dishwasher inlet connection.
- Incorrect drain hose routing.
- A knockout plug left in place after installation.
What Is a Garbage Disposal Knockout Plug?
A knockout plug is a removable factory-installed plug that closes the dishwasher inlet on certain new garbage disposals.
When a compatible dishwasher connection is installed, this plug must be removed to allow wastewater to enter the disposal.
If the plug remains in place, the dishwasher may be unable to drain through that connection.
When Should You Suspect This Problem?
Consider it when:
- The dishwasher is newly installed.
- The garbage disposal was recently replaced.
- The problem started immediately after installation.
- The sink drains normally, but the dishwasher does not.
Correcting the connection requires following the disposal manufacturer's instructions.
Do not attempt to remove the knockout plug while the disposal is connected to power.
Never place your hands inside the disposal.
A qualified installer can correct the problem safely.
Could the Dishwasher Drain Pump Be Bad?
The drain pump moves wastewater out of the dishwasher.
If it becomes blocked or malfunctions, water may remain in the tub.
Possible Symptoms
- Standing water after the wash cycle.
- Humming or buzzing during attempted drainage.
- Scraping or rattling noises.
- A drain-related error code.
- Persistent drainage failure after cleaning the filter and checking the sink drain.
Does Humming Mean the Drain Pump Is Bad?
Not necessarily.
A humming noise may occur when the system attempts to drain but water cannot move through the drainage path properly.
A blockage, mechanical issue, or another problem may be responsible.
The sound alone cannot confirm a defective pump motor.
Can I Clean the Drain Pump Myself?
It depends on the dishwasher model.
For example, Bosch provides specific pump-area cleaning procedures for certain dishwashers.
On compatible models, the procedure may allow the homeowner to remove a designated cover and clear accessible debris after safely disconnecting power.
Other dishwashers require technical disassembly to reach the pump.
Never assume that a cleaning procedure for one brand applies to every dishwasher.
Do not insert tools into the impeller area, touch unknown internal components, or test the pump's electrical supply.
If broken glass, sharp objects, or service-panel removal are involved, contact a qualified technician.
Troubleshooting by Symptom
| Symptom | Possible Causes | Recommended Next Step |
|---|---|---|
| Water remains after the cycle | Filter, drain hose, or pump problem | Start with the filter |
| Water remains only inside the filter area | Normal residual water on some models | Check the manual |
| Dishwasher drains slowly | Partial blockage | Check the filter, sink, and accessible hose |
| Water flows back into the dishwasher | Drain installation or backflow problem | Check the air gap, high loop, or connection |
| Newly installed dishwasher has never drained | Installation error or knockout plug | Have the installation checked |
| Sink and dishwasher both drain poorly | Household plumbing blockage | Check the kitchen sink drain |
| Pump hums but water does not drain | Obstruction or mechanical problem | Manufacturer-approved inspection or service |
| Scraping noise during drainage | Possible foreign object | Stop using the machine and arrange inspection |
| No draining sound | Cycle, control, pump, or electrical issue | Check the program and error messages |
| Water leaks during draining | Damaged hose or connection | Stop operation and address the leak |
| Drain-related error code | Drainage system problem detected | Consult the model-specific manual |
Use this table to guide troubleshooting, not to confirm a particular component failure.
Possible Solutions
Safe Homeowner Checks
Depending on the model, you may be able to:
- Confirm that the cycle finished.
- Use Cancel/Drain according to the manual.
- Carefully remove standing water.
- Clean the removable filter.
- Remove visible, accessible debris.
- Check whether the sink drains normally.
- Look for kinks in accessible drain hose sections.
- Check for signs of a garbage disposal blockage.
- Visually inspect the air gap or high loop installation.
- Record error codes.
Manufacturer-Approved Maintenance
Depending on the dishwasher model, homeowners may be allowed to:
- Clean the filter and accessible sump area.
- Remove and clean a pump cover specifically designed for homeowner access.
- Clean accessible air gap components.
- Correct accessible hose positioning when authorized.
- Reinstall removable maintenance parts.
Repairs That Require a Professional
Professional service may be needed for:
- Drain pump replacement.
- Repairs involving internal pump components.
- Inaccessible drain hose blockages.
- Garbage disposal connection corrections.
- Knockout plug removal during installation.
- Internal hose repairs or replacement.
- Sensor and electronic control repairs.
- Electrical diagnosis.
- Plumbing installation corrections requiring disassembly.
If the blockage is in household plumbing, a plumber may be the appropriate professional.
Safety Precautions
How to Prevent Dishwasher Drainage Problems
Preventive maintenance depends on the dishwasher model and how it is used.
Helpful practices include:
- Clean the filter as frequently as the manufacturer recommends.
- Remove large food scraps before loading dishes.
- Keep packaging labels and other nonfood materials out of the dishwasher.
- Make sure the filter is correctly installed after cleaning.
- Use only detergent intended for automatic dishwashers.
- Avoid overloading the dish racks.
- Keep the kitchen sink drain functioning properly.
- Check accessible air gap components periodically if the installation includes one.
- Watch for drainage changes after plumbing work or garbage disposal replacement.
Do not perform technical maintenance that the manufacturer does not recommend.
How Much Does It Cost to Fix a Dishwasher That Is Not Draining?
Repair costs depend on the cause.
A clogged filter may only require cleaning.
A kinked drain hose or simple installation issue may also be corrected without replacing major components, depending on accessibility.
Problems involving the drain pump, electronic controls, or internal plumbing may require replacement parts and professional labor.
Before approving service, ask about:
- The service call fee.
- Diagnostic charges.
- The confirmed cause.
- Replacement part costs.
- Labor costs.
- Repair warranty.
- Manufacturer warranty coverage.
If the blockage is in household plumbing, a plumber's charges may need to be considered separately.
Do not approve drain pump replacement without a confirmed diagnosis.
Should You Repair or Replace a Dishwasher That Is Not Draining?
When to Call a Professional
Contact an appliance technician if:
- The dishwasher still does not drain after cleaning the filter.
- An obstruction is located in an inaccessible area.
- The drain pump makes persistent abnormal noises.
- Error codes continue appearing.
- Wastewater repeatedly flows back into the tub.
- The drain hose or connections are leaking.
- The drain hose must be disconnected to investigate the problem.
- A garbage disposal knockout plug or connection problem is suspected.
- The installation may not meet manufacturer instructions or local plumbing requirements.
- Electrical warning signs are present.
- Diagnosis requires service-panel removal or electrical testing.
If the blockage is in the kitchen drain, contact a plumber.
Frequently Asked Questions
Why is my dishwasher not draining?
Common causes include a clogged filter, food debris around the drain, a kinked hose, a blocked garbage disposal connection, or a drain pump issue. Start with basic checks before assuming a component has failed.
Can I clean my dishwasher filter myself?
Yes, if your dishwasher has a removable filter intended for homeowner maintenance. Follow the manufacturer's instructions for safely disconnecting power, removing the filter, cleaning it, and reinstalling it correctly.
Is it normal to have a little water in the bottom of a dishwasher?
On certain models, a small amount of water inside the sump or filter area is normal. However, standing water covering the tub floor after a completed cycle may indicate a drainage problem.
Can a garbage disposal prevent a dishwasher from draining?
Yes. If the dishwasher drains through the disposal and the connection or household drain is blocked, wastewater may not flow properly. On new installations, a knockout plug left in the disposal inlet can also prevent drainage.
What happens if the dishwasher drain hose is kinked?
A kink may restrict water flow and cause slow or incomplete drainage. Inspect only accessible hose sections and follow manufacturer-approved procedures for corrections.
How do I know if my dishwasher drain pump is bad?
Standing water, unusual noises, and persistent drainage failures may be associated with the pump. However, blockages and installation problems can produce similar symptoms. Professional diagnosis may be necessary.
Can I use chemical drain cleaner in my dishwasher?
No. Chemical products intended for clearing sink drains may damage dishwasher components and create safety hazards. Use only cleaning methods and products approved by the dishwasher manufacturer.
Related Guides
This guide offers general information. Steps, parts and costs vary by brand, model and location — your owner's manual takes precedence. For electrical, gas or complex repairs, contact a qualified professional.