Why Does My Dishwasher Smell Bad?
Quick Answer
If your dishwasher smells bad, the most common causes include food debris trapped in the filter, grease buildup, standing water, drainage problems, or residue around the door gasket.
In many cases, proper cleaning and regular maintenance can eliminate the odor.
Start with these checks:
Remove the dishes and look for food debris at the bottom of the dishwasher.
Clean the removable filter according to the owner's manual.
Check for an unusual amount of standing water.
Clean the door edges and rubber gasket.
Inspect accessible spray arms for debris.
Make sure the kitchen sink and garbage disposal drain properly.
Run a manufacturer-approved dishwasher cleaning cycle.
If the odor persists, particularly if it smells like sewage or occurs alongside dirty water backing up into the dishwasher, there may be a problem with the drainage system.
Safety warning: A burning smell, smoke, or a strong chemical odor should not be treated as a routine cleaning issue. Stop using the dishwasher and seek qualified assistance.
In this guide
Why Does My Dishwasher Smell Bad?
Dishwashers use water and detergent to remove grease, food particles, and other residue from dishes.
During washing, some of these materials are collected by the filter or remain on interior surfaces.
Over time, accumulated residue can develop unpleasant odors.
Common causes include:
- Food particles trapped in the dishwasher filter.
- Grease buildup at the bottom of the tub.
- Debris collecting in spray arm openings.
- Food residue along the door edges.
- Moisture and organic residue around the door gasket.
- Dirty water that does not drain properly.
- Wastewater backing up from the kitchen sink.
- Dirty dishes sitting in the dishwasher for several days.
- Infrequent cleaning and maintenance.
An unpleasant smell does not automatically mean the dishwasher is damaged.
However, odors that persist after thorough cleaning may indicate a problem beyond the accessible interior surfaces.
Most Common Causes of Dishwasher Odors
| Possible Cause | Common Symptom | What to Check | First Solution |
|---|---|---|---|
| Dirty dishwasher filter | Rotten food smell | Food debris in the filter | Clean according to the manual |
| Food residue in the tub | Odor after multiple cycles | Bottom and interior corners | Remove visible debris |
| Grease buildup | Rancid or stale odor | Interior surfaces | Run an approved cleaning cycle |
| Dirty spray arms | Recurring debris and odor | Accessible spray arm openings | Clean according to the manufacturer |
| Standing water | Strong odor with visible water | Bottom of the tub | Investigate drainage |
| Clogged drain hose | Persistent odor with poor draining | Drainage symptoms and accessible hose sections | Arrange service when necessary |
| Sink wastewater backing up | Sewage-like odor | Sink drain, air gap, and hose installation | Plumbing inspection |
| Dirty garbage disposal | Odor near the sink and dishwasher | Disposal and sink drainage | Clean safely according to its manual |
| Dirty door gasket | Musty odor around the door | Gasket folds and door edges | Clean and dry |
| Infrequent dishwasher use | Odor after dirty dishes sit for days | Usage habits | Run a rinse or wash cycle more regularly |
| Incorrect detergent | Residue, excess suds, or lingering odor | Detergent type and dosage | Correct according to the manual |
| New appliance materials | Mild plastic smell during initial use | Recent installation | Follow manufacturer guidance |
| Electrical malfunction | Burning smell | Smoke, abnormal heat, or unusual operation | Stop using the appliance and arrange service |
No particular odor, by itself, confirms a mechanical or electrical failure.
Troubleshooting by Type of Smell
Dishwasher Smells Like Rotten Food
A rotten food smell is one of the most common dishwasher odor complaints.
It may develop when food particles remain in the filter, along the door edges, or in accessible areas of the wash system.
What to check:
- Dishwasher filter.
- Bottom of the tub.
- Area surrounding the filter.
- Interior door edges.
- Food debris left on dishes.
- Accessible spray arm openings.
Next step: Clean the filter and accessible surfaces before running a maintenance cleaning cycle.
Dishwasher Smells Like Sewage
A sewage-like smell deserves particular attention, especially if dirty water is backing up into the dishwasher.
Possible causes include:
- A clogged kitchen sink drain.
- Incorrect drain hose installation.
- A missing or improperly installed backflow prevention arrangement.
- A blockage in the drainage path.
- A problem with the garbage disposal connection.
A sewage-like odor alone does not prove that the drain installation is incorrect.
However, if wastewater is returning to the dishwasher, the plumbing system needs to be checked.
Next step: Inspect accessible drainage conditions and contact a qualified plumber or appliance technician when necessary.
Dishwasher Smells Musty or Moldy
A musty smell may be associated with persistent moisture and organic residue around the door gasket, interior edges, or other surfaces.
Check for:
- Dirt around the door gasket.
- Water remaining in accessible areas.
- Long periods without use.
- Residue along interior door edges.
- Infrequent cleaning.
A musty odor does not, by itself, confirm the presence of a particular type of mold.
Next step: Clean and dry accessible surfaces and address any drainage problem.
Dishwasher Smells Greasy or Rancid
Grease and food residue can accumulate on interior surfaces, particularly when routine maintenance is neglected.
This may occur even when the filter does not appear especially dirty.
Next step: Run a cleaning cycle using a dishwasher cleaner approved for your model.
New Dishwasher Smells Like Plastic
Some new dishwashers may have a mild initial odor from manufacturing materials.
This smell may decrease during the first several cycles.
However, a normal new-appliance smell should not be confused with a strong burning plastic odor.
If you notice smoke, abnormal overheating, or signs of melting components, stop using the appliance and arrange professional inspection.
Dishwasher Smells Like Something Is Burning
A burning smell may involve an object contacting a hot component or an electrical malfunction.
Do not run a cleaning cycle to try to remove a burning smell.
Stop using the dishwasher, disconnect electrical power only if it is safe to do so, and contact a qualified technician.
What to Check First
Before using cleaning products, try to identify where the odor originates.
Check the Dishwasher Filter
The removable filter is typically located at the bottom of the tub.
Trapped food particles may produce odors as they accumulate.
Look for Standing Water
A small amount of water in the filter or sump area may be normal on certain dishwasher models.
However, water covering the tub floor after a completed cycle may indicate a drainage problem.
Inspect the Door Gasket
The folds of the gasket and interior door edges can collect food residue, grease, and moisture.
Check the Kitchen Sink Drain
If the kitchen sink also smells bad or drains slowly, the odor may be related to household plumbing.
Consider How Often the Dishwasher Is Used
Leaving dirty dishes in the dishwasher for several days can contribute to unpleasant odors.
Some manufacturers recommend using a rinse cycle when dishes will not be washed immediately.
How to Clean a Smelly Dishwasher: Step-by-Step
Step 1: Empty the Dishwasher
Remove all dishes, glasses, silverware, and cookware.
Look for large food scraps at the bottom of the tub.
Allow the dishwasher to cool after its last cycle.
Before removing filters or performing maintenance, follow the manufacturer's instructions for safely disconnecting power.
Step 2: Remove and Clean the Filter
If your dishwasher has a removable filter intended for homeowner maintenance:
- Remove the lower dish rack.
- Locate the filter assembly.
- Unlock it according to the owner's manual.
- Carefully remove the filter.
- Rinse it under running water.
- Use a soft brush and mild dish soap if recommended.
- Remove accumulated food debris.
- Rinse thoroughly.
- Reinstall and lock the filter correctly.
Do not use wire brushes or abrasive cleaning products.
Never run the dishwasher without its filter when the manufacturer requires the filter to be installed.
Step 3: Clean the Bottom of the Tub
With the filter removed, if permitted by the manufacturer, inspect accessible areas.
Look for:
- Food scraps.
- Packaging labels.
- Small pieces of packaging.
- Seeds.
- Greasy residue.
- Foreign objects.
Use a soft cloth or sponge to remove accessible debris.
Be careful around broken glass or sharp objects.
Do not reach into unfamiliar openings or attempt to access internal pump components.
Step 4: Clean the Interior Door Edges
Some areas around the dishwasher door do not receive the same water spray as the main tub.
As a result, residue may accumulate there.
Use a soft cloth dampened with warm water and a mild cleaning product approved by the manufacturer.
Clean:
- Interior door edges.
- Accessible areas near the hinges.
- The lower door edge.
- Areas where food residue collects.
Do not pour or spray excessive water directly onto electronic controls, door latches, or electrical components.
Step 5: Clean the Door Gasket
The rubber door gasket helps prevent water from leaking out of the dishwasher.
Food residue and moisture can collect in its folds.
Safe cleaning procedure:
- Use a soft cloth.
- Apply only a manufacturer-approved cleaning product.
- Remove visible residue.
- Gently clean accessible gasket folds without stretching the rubber.
- Dry the area with a clean cloth.
Do not use stiff brushes, sharp tools, or corrosive cleaners.
If the gasket is torn or deformed, ask about proper replacement.
Step 6: Inspect the Spray Arms
The spray arms distribute water during the wash cycle.
Debris in their openings may interfere with water circulation and cleaning performance.
Visually inspect accessible spray arms.
If the manufacturer allows removal, follow the model-specific cleaning procedure.
Do not use drill bits or tools that could enlarge the spray openings.
Step 7: Check for Drainage Problems
Before running a cleaning cycle, make sure the dishwasher drains properly.
Warning signs include:
- Water covering the bottom of the tub after a completed cycle.
- Dirty water returning between washes.
- Slow draining.
- Unusual drain pump noises.
- Drain-related error messages.
If the dishwasher is not draining, address the problem before continuing.
A dishwasher cleaning product cannot repair a clogged drain hose or defective pump.
Step 8: Run a Dishwasher Cleaning Cycle
After properly reinstalling the filter and other removable components, run a cleaning cycle approved by the manufacturer.
Depending on the model, this may involve:
- A dishwasher cleaning product.
- A dedicated maintenance cycle.
- An empty wash cycle at the recommended temperature.
- A specific procedure for removing grease or mineral deposits.
Bosch recommends dishwasher cleaning and descaling products for applicable models.
Whirlpool also provides dishwasher cleaning guidance and, for certain models, instructions involving white vinegar.
Do not assume that vinegar is appropriate for every dishwasher. Always check the owner's manual before using it.
Never mix cleaning products.
Step 9: Check the Results
After cleaning:
- Confirm that the water drained properly.
- Check whether the odor has improved.
- Make sure the filter is correctly installed.
- Look for leaks.
- Monitor the results of the next normal wash cycle.
If the odor returns quickly, the underlying cause may not have been resolved.
Standing Water: When Is It Normal?
Water remaining in the dishwasher should be evaluated carefully.
Some dishwashers are designed to retain a small amount of water in the filter or sump area.
This water may help protect certain internal seals.
Therefore, not every trace of residual water indicates a malfunction.
| Situation | Possible Explanation | Recommended Action |
|---|---|---|
| Small amount of water in the sump | May be normal for the model | Check the owner's manual |
| Water covering the tub floor | Possible incomplete drainage | Inspect filter and cycle operation |
| Dirty water returns hours later | Possible wastewater backflow | Check the drain installation |
| Standing water with sewage odor | Possible plumbing or drainage issue | Check sink, air gap, and connections |
| Slow draining with debris | Filter, hose, or pump problem | Begin with accessible checks |
| Standing water with an error code | Drain-related problem detected | Consult the model-specific manual |
If drainage is not working correctly, cleaning should be combined with investigating the underlying problem.
Can Drainage Problems Make a Dishwasher Smell Bad?
Yes.
When wastewater does not drain properly, food residue and contaminated water may remain inside the appliance.
Odors may also develop if wastewater from the sink flows back into the dishwasher.
Clogged Filter
Accumulated debris may restrict water circulation and drainage.
Drain Hose Problems
The dishwasher drain hose carries wastewater from the appliance to the household drain.
Kinks, blockages, or improper positioning may contribute to drainage problems.
What Is a High Loop?
A high loop is a drain hose configuration in which the hose rises to an elevated point before connecting to the drain.
When permitted and installed correctly, this arrangement can help reduce wastewater backflow.
What Is an Air Gap?
An air gap is a plumbing device that creates a physical separation in the drainage path, usually near the kitchen sink.
Its purpose is to help prevent contaminated water from flowing backward into the dishwasher.
Some U.S. jurisdictions require an air gap.
A high loop is not automatically an acceptable substitute when local plumbing codes require an air gap.
Garbage Disposal Connection
In the United States, many dishwashers connect to a kitchen sink garbage disposal.
If the disposal or household drain becomes clogged, wastewater may back up and contribute to odors.
Do not disconnect plumbing or attempt to clear inaccessible pipes without appropriate training.
Installation problems should be evaluated by a qualified installer or plumber.
Can a Dirty Door Gasket Cause Dishwasher Odors?
Yes.
The folds of the door gasket may trap food particles, grease, and moisture.
Without regular cleaning, this buildup can develop an unpleasant smell.
What to Look For
- Accumulated residue.
- Dirt trapped in the folds.
- Persistent moisture.
- Visible surface buildup.
- Tears or deformation.
How to Clean the Gasket
Use a soft cloth and the cleaning method recommended by the manufacturer.
Remove residue without stretching or pulling the rubber.
Dry accessible areas afterward.
If the gasket is damaged or the dishwasher is leaking, arrange appropriate service.
Do not use hair dryers, heaters, or harsh chemicals to reshape the gasket.
What Is the Best Way to Remove Dishwasher Odors?
The most effective solution depends on the source.
| Source of Odor | Recommended First Step |
|---|---|
| Food trapped in the filter | Clean the filter |
| Debris in the bottom of the tub | Remove accessible food residue |
| Grease buildup | Run a manufacturer-approved cleaning cycle |
| Dirty door gasket | Clean and dry the gasket |
| Dirty dishes sitting for several days | Use a rinse cycle or wash more regularly |
| Excessive standing water | Investigate drainage |
| Wastewater backing up from the sink | Check plumbing and drain installation |
| Odor persists after thorough cleaning | Arrange professional diagnosis |
| Burning smell | Stop using the appliance and seek service |
Avoid using fragrances simply to cover up odors.
Removing the buildup or correcting the condition causing the smell is more effective than masking it.
Can You Clean a Dishwasher With Vinegar?
It depends on the manufacturer's recommendations.
Whirlpool provides white vinegar cleaning procedures for certain dishwasher models.
Other manufacturers recommend specific dishwasher cleaning and descaling products.
For this reason, vinegar should not be presented as a universal cleaning solution.
Before using vinegar:
- Check the owner's manual.
- Confirm that the manufacturer allows it.
- Follow the specified quantity and procedure.
- Do not mix it with other cleaning products.
- Avoid concentrated vinegar or other acidic products unless approved.
Never mix vinegar with chlorine bleach. This combination can release toxic chlorine gas.
Never mix bleach with ammonia or other household cleaning products.
For a generally applicable approach, choose a dishwasher cleaner specifically approved for your appliance and follow its instructions.
How Often Should You Clean Your Dishwasher?
Cleaning frequency depends on the dishwasher model, how often it is used, and local water conditions.
Some manufacturers recommend cleaning removable filters approximately once a month.
Households that run the dishwasher daily or regularly wash heavily soiled dishes may need more frequent filter maintenance.
Deep cleaning and descaling intervals may be different.
Suggested Preventive Maintenance Schedule
| Frequency | Maintenance Task |
|---|---|
| After each use | Check for large visible food scraps |
| Regularly | Inspect the filter and door gasket for buildup |
| As recommended by the manufacturer | Clean the removable filter |
| Periodically | Clean accessible spray arms |
| According to the owner's manual | Run an interior maintenance cleaning cycle |
| When mineral deposits develop | Consider approved hard water or descaling maintenance |
| When odors persist | Investigate drainage and other underlying causes |
Routine household maintenance should not require removing internal service panels.
How to Prevent Dishwasher Odors From Coming Back
Several habits can help reduce unpleasant smells.
Scrape Large Food Scraps Off Dishes
Avoid placing bones, packaging materials, labels, and large amounts of food debris inside the dishwasher.
A complete pre-rinse is generally unnecessary, but larger food scraps should be removed.
Do Not Leave Heavily Soiled Dishes Sitting for Days
If you are not ready to run a full wash cycle, consider using a Rinse Only or Rinse and Hold program when available and recommended.
Keep the Filter Clean
Routine filter cleaning reduces accumulated organic debris.
Avoid Overloading the Racks
Overloading can restrict water circulation and reduce cleaning performance.
Use the Correct Detergent
Use only detergent intended for automatic dishwashers.
Follow the recommended dosage for the model and load.
Use an Appropriate Wash Cycle
Very short cycles may not provide adequate cleaning for greasy cookware or dried-on food.
Manage Moisture
After the cycle ends and the dishwasher cools, follow the manufacturer's recommendations for drying the interior.
If the manual allows leaving the door slightly open, do so only when safe, especially in homes with children or pets.
Watch for Drainage Problems
If odors return along with standing dirty water, do not simply repeat cleaning cycles.
The drainage problem needs to be investigated.
Dishwasher Odor Troubleshooting Decision Tree
Decision 1: Is There a Burning Smell or Smoke?
Yes.
Stop using the dishwasher and seek professional assistance.
No.
Continue to Decision 2.
Decision 2: Is There Food Debris in the Filter?
Yes.
Clean and reinstall the filter according to the manual.
No.
Continue to Decision 3.
Decision 3: Is There an Excessive Amount of Standing Water?
Yes.
Investigate drainage before running additional cycles.
No.
Continue to Decision 4.
Decision 4: Is There Residue Around the Door Gasket or Interior Edges?
Yes.
Clean and dry the accessible surfaces.
No.
Continue to Decision 5.
Decision 5: Does the Odor Seem to Come From the Sink or Drain?
Yes.
Check sink drainage, the garbage disposal, and the drain hose installation.
Contact a plumber if necessary.
No.
Continue to Decision 6.
Decision 6: Have You Run an Appropriate Dishwasher Cleaning Cycle?
No.
Run a maintenance cycle using a manufacturer-approved cleaner.
Yes.
Continue to Decision 7.
Decision 7: Does the Odor Persist or Return Quickly?
Yes.
Inaccessible residue, drainage problems, or another malfunction may be responsible.
Next step: Arrange professional inspection.
No.
Continue the preventive maintenance recommended by the manufacturer.
Safety Precautions
How Much Does It Cost to Fix a Smelly Dishwasher?
In many cases, dishwasher odors can be resolved with routine cleaning, without replacing any components.
Costs may be limited to manufacturer-approved cleaning products.
However, if the smell is related to drainage problems, additional work may be necessary, such as:
- Professional drain cleaning.
- Correcting improper plumbing installation.
- Repairing the drain hose.
- Replacing damaged components.
- Diagnosing the drain pump.
Before approving service, ask about:
- The service call fee.
- Diagnostic charges.
- The confirmed cause.
- Replacement part costs.
- Labor charges.
- Repair warranty.
If the source is household plumbing, a plumber may be needed.
Should You Clean, Repair, or Replace the Dishwasher?
An unpleasant smell alone rarely justifies replacing the dishwasher.
Cleaning May Be Enough When:
- Food debris is trapped in the filter.
- Residue has accumulated around the door.
- Maintenance has been neglected.
- Drainage works correctly.
- The smell disappears after cleaning.
Repair May Be Necessary When:
- There is an inaccessible blockage.
- The dishwasher does not drain properly.
- Dirty water repeatedly backs up.
- An internal component has failed.
- The odor returns despite proper cleaning.
Replacement May Be Worth Considering When:
- The dishwasher has multiple problems.
- Malfunctions keep returning.
- Repair costs are unusually high.
- Essential replacement parts are unavailable.
- The overall condition makes repair impractical.
Consider the dishwasher's age, condition, efficiency, and actual repair estimate.
When to Call a Professional
Contact a qualified appliance technician if:
- The smell persists after thorough cleaning.
- Dirty water repeatedly backs up into the dishwasher.
- The dishwasher does not drain properly.
- The drain pump makes unusual noises.
- Water leaks near connections.
- A sewage-like odor occurs with plumbing problems.
- The door gasket is damaged.
- Error codes continue appearing.
- Diagnosis requires removing technical panels.
- You notice smoke, burning smells, or electrical warning signs.
If the source is the kitchen sink or household drain, contact a plumber.
Frequently Asked Questions
Why does my dishwasher smell bad?
Common causes include food debris trapped in the filter, grease buildup, residue on interior surfaces, standing water, and drainage problems.
How do I get rid of a bad smell in my dishwasher?
Start by cleaning the filter, the bottom of the tub, and the door gasket. Then run a manufacturer-approved dishwasher cleaning cycle. If the odor persists, check for drainage problems.
Can a dirty dishwasher filter cause bad smells?
Yes. Food particles trapped in the filter can break down and produce unpleasant odors. Regular cleaning is an important preventive measure.
Is it normal to have water in the bottom of a dishwasher?
A small amount of water in the sump may be normal on certain models. However, water covering the tub floor or returning from the sink requires investigation.
Can I use vinegar to clean my dishwasher?
Only if the manufacturer allows it. Some brands provide specific white vinegar cleaning procedures, while others recommend dedicated dishwasher cleaners. Never mix vinegar with chlorine bleach.
Why does my dishwasher smell like sewage?
Drainage problems or wastewater backing up from the kitchen sink may be responsible. Check the drain hose, air gap, or high loop installation according to the manual and local plumbing requirements. The smell alone cannot confirm the cause.
How often should I clean my dishwasher filter?
It depends on the model and usage. Some manufacturers recommend monthly cleaning, while heavy use may require more frequent maintenance. Consult your dishwasher's manual.
Can a burning smell be removed with a dishwasher cleaning cycle?
No. A burning smell may indicate a safety hazard. Stop using the dishwasher and arrange professional inspection before operating it again.
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.