What Causes a Dishwasher to Smell Bad and How to Fix It
Quick answer
A smelly dishwasher is often caused by trapped food particles, mold, or a dirty filter. Clean the filter, run a vinegar cycle, and check for mold in the seals and drain.
Confirm the symptom
- Notice a foul odor when opening the dishwasher
- Smell lingering after a wash cycle
- Dishes have a musty or moldy smell
Tools and prep
- White vinegar — Natural cleaner to remove buildup
- Baking soda — Absorbs odors and cleans surfaces
- Soft brush — Scrub filters and hard-to-reach areas
- Microfiber cloth — Wipe down interior surfaces
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Prep & safety
- Unplug the dishwasher for safety before cleaning.
- Remove any dishes or debris from the dishwasher.
Step-by-step troubleshooting
Clean the Filter
Do: Locate the filter at the bottom of the dishwasher and remove it. Use a soft brush and warm water to scrub away debris.
Observe: The filter is clogged with food particles and grime.
Means: A dirty filter is causing the odor.
Next: Rinse the filter and reinstall it.
Run a Vinegar Cycle
Do: Place a cup of white vinegar in a dishwasher-safe container on the top rack. Run a hot water cycle without dishes.
Observe: The vinegar neutralizes odors and dissolves buildup.
Means: Mineral deposits or mildew are contributing to the smell.
Next: Wipe down the interior with a microfiber cloth.
Check for Mold
Do: Inspect the rubber seals, door gasket, and drain area for mold or mildew.
Observe: Black or green mold is present in the seals or drain.
Means: Mold growth is the source of the odor.
Next: Scrub the affected areas with a baking soda paste.
Clean the Drain
Do: Use a soft brush to clean the drain area at the bottom of the dishwasher.
Observe: The drain is clogged with debris or has standing water.
Means: A blocked drain is causing the smell.
Next: Flush the drain with hot water.
Wipe Interior Surfaces
Do: Use a microfiber cloth and baking soda to wipe down the interior walls and door.
Observe: The interior has a film or residue.
Means: Residue buildup is contributing to the odor.
Next: Dry the interior with a clean cloth.
Check for Standing Water
Do: Ensure the dishwasher is completely empty of water after each cycle.
Observe: Standing water remains in the bottom of the dishwasher.
Means: Standing water promotes mold and bacteria growth.
Next: Use a towel to dry the interior if necessary.
Common causes table
| Cause | Why | Likelihood | Difficulty | Part often needed |
|---|---|---|---|---|
| Clogged Filter | Trapped food particles decompose and cause odors. | High | Easy | Filter |
| Mold or Mildew | Moisture and food residue create a breeding ground for mold. | High | Easy | None |
| Dirty Interior | Residue from dishes and detergent builds up over time. | Medium | Easy | None |
| Clogged Drain | Debris in the drain prevents proper water flow and causes standing water. | Medium | Easy | None |
| Standing Water | Water left in the dishwasher after cycles promotes bacterial growth. | Medium | Easy | None |
| Hard Water Deposits | Mineral buildup can cause a musty smell and affect cleaning performance. | Low | Easy | Descaler |
Parts matching
If you need to replace the filter or descaler, match the following specifications:
- Filter: model number and size (check your dishwasher manual)
- Descaler: compatible with your dishwasher model
Purchase replacement parts directly from the manufacturer or a trusted appliance parts supplier.
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When to call a pro
- The odor persists after multiple cleaning attempts
- You notice a foul smell coming from the drain pipe or garbage disposal
- The dishwasher is not draining properly despite cleaning
- You suspect a deeper mold infestation inside the dishwasher
- The dishwasher is making unusual noises along with the odor
FAQ
How often should I clean my dishwasher filter?
Clean the filter at least once every 1–2 months to prevent clogs and odors.
Can I use bleach to clean my dishwasher?
Avoid using bleach as it can damage the dishwasher's interior and leave harmful residues. Use vinegar or baking soda instead.
Why does my dishwasher smell like rotten eggs?
A rotten egg smell is often caused by bacterial growth in the drain or standing water. Clean the drain and ensure proper drainage.
Will running a hot water cycle help with the odor?
Yes, a hot water cycle with vinegar can help eliminate odors by dissolving buildup and killing bacteria.
Can a smelly dishwasher affect the taste of my dishes?
Yes, lingering odors can transfer to dishes, especially if the dishwasher is not cleaned regularly.