Symptoms: Smells

Dishwasher Smells Bad? Where the Odor Is Actually Coming From

A sour or rotten-egg smell is almost never a broken part. It’s trapped food debris and standing water the spray can’t reach, usually in the filter or door gasket.

Risk: Low
Difficulty: Beginner
Estimated time: 15 to 30 minutes

Before you start

Unplug the appliance, shut off the water supply if relevant, and stop immediately if you smell burning. If in doubt, call a qualified professional.

On this page

Tools needed
Probable causes
First checks
Step-by-step diagnosis
Mistakes to avoid
When to stop
Parts involved
When to call a professional

A bad smell from the dishwasher is almost always a cleaning problem, not a mechanical one, and it’s one of the few dishwasher complaints you can usually fix for free in under 30 minutes. The filter and the door gasket trap the most food debris and are the first places to check before you look anywhere else.

This page is part of our full dishwasher troubleshooting guide. If dishes are coming out dirty as well as smelly, our dishwasher not cleaning guide covers that separately.

Quick Diagnosis Table

Cause	Likelihood	Difficulty	Typical Cost
Debris in the lower filter	Very likely	Easy	$0
Grime in the door gasket	Likely	Easy	$0
Standing water (drain issue)	Likely	Varies	See not-draining guide
Grease film in tub/spray arms	Possible	Easy	$0–5 (vinegar)
Wrong detergent	Possible	Easy	$0
Plumbing venting issue	Rare	Professional recommended	Varies

Repair or Replace?

There’s effectively nothing to repair or replace here. This is a cleaning issue in nearly every case, and the fix costs nothing but a bit of time. If odor keeps returning within days of a thorough cleaning, revisit the drainage checks in our not-draining guide, since a partial blockage that lets water sit is a common repeat offender.

Frequently Asked Questions

How often should I clean the dishwasher filter?

Once a month for most households, more often if you regularly run dishes with heavy food residue or don't pre-scrape.

Is it safe to use bleach to clean a smelly dishwasher?

Only on a stainless-interior model, and never combined with vinegar in the same session. For most plastic-tub dishwashers, stick to dish soap and a vinegar rinse cycle instead.

Why does my dishwasher smell like rotten eggs specifically?

A sulfur smell often points to bacteria in standing water or, less commonly, to sewer gas venting back through the drain line — persistent sulfur odor after cleaning is worth a plumber's look.

Can a dirty dishwasher smell affect how clean my dishes get?

Yes indirectly — the same grease and food film causing the odor also coats the spray arms and can leave dishes cloudy or greasy.

Do dishwasher cleaning tablets actually work?

Commercial cleaning tablets are a reasonable substitute for the vinegar cycle, but they don't replace manually cleaning the filter and gasket, which is where most of the smell originates.

The information provided here is a diagnostic aid and does not replace the intervention of a qualified professional.

Tools needed

Old toothbrush or small brush
Dish soap
White vinegar
Flashlight
Gloves

Probable causes

Very likely Food debris trapped in the lower filter
Likely Grime or mildew in the door gasket folds
Likely Standing water from a partial drain issue
Possible Grease film built up inside the tub and spray arms
Possible Wrong detergent used, causing sour buildup
Rare Rotten-egg smell venting back from the disposal or drain line

First checks

Remove and inspect the lower filter — this is where most odors originate.
Run a finger along the inside folds of the rubber door gasket and check for slime or visible mildew.
Check for standing water at the bottom of the tub, which points to a drainage issue rather than pure buildup.
Smell the drain hose connection point and garbage disposal separately to rule out the odor coming from the plumbing rather than the dishwasher itself.

Step-by-step diagnosis

Hand-wash the filter assembly with dish soap and a soft brush, working debris out of the mesh screen, then reinstall it fully seated and locked.
Wipe down the entire door gasket with a damp cloth and mild soap, paying close attention to the bottom fold where water collects.
Place a cup of white vinegar upright on the top rack and run a hot, empty cycle to break down grease film in the tub and spray arms.
Check and clear the spray arm jets with a toothpick if the vinegar cycle doesn't fully resolve the smell — clogged jets leave grease behind instead of rinsing it away.
If the smell persists after cleaning, work through the drain checks in our not-draining guide, since standing water is a common hidden cause.

Mistakes to avoid

Using bleach and vinegar in the same cycle or close together — never combine them, as this produces toxic chlorine gas.
Masking the smell with dishwasher fresheners without cleaning the filter first — it treats the symptom, not the cause, and debris keeps accumulating.

When to stop

A persistent rotten-egg smell that doesn't improve with cleaning may be a plumbing venting issue rather than the dishwasher — worth a plumber's opinion.

Parts potentially involved

When to call a professional

If the simple checks didn’t solve it, if the fix involves electrical wiring, gas, or the refrigerant circuit, or if you have any doubt at all: stop there and hand the appliance to a qualified repair professional.

Related guides

Error codes for this appliance

The information provided here is a diagnostic aid and does not replace the intervention of a qualified professional.

July 20, 2026

Sam Radford — DiagnosFix

Technical reviewer

Last verified: 2026-07-17