Dishwasher Smells Bad? Remove Odors and Find the Cause

Dishwasher smells bad when food, grease and standing water collect where the wash cycle does not reach: the filter, the sump, the door gasket, the spray arms and the drain line. Start by cleaning those parts by hand, then run a hot cycle with a cleaner.

If a sewer-like smell persists, the problem is likely in the drain, not the dishwasher itself.

Dishwasher smells bad: the quick answer

Most odours come from food debris trapped in the filter and sump, mildew on the rubber door gasket, and stale water in the drain hose. Clean those, and the smell usually goes. If it smells like sewage or rotten eggs even after cleaning, check the drain connection, air gap and disposal, because drain-line gases can back up into the tub.

Quick facts: dishwasher smells bad
Time needed	20 to 45 minutes, plus one hot cycle
Tools	Soft brush, toothpick, cloth, white vinegar or citric acid, baking soda
Difficulty	Easy
Do not	Mix bleach with vinegar or other cleaners

Step-by-step deep clean

1. Empty the dishwasher and remove the lower rack.
2. Remove and wash the filter, scrubbing off grease and grit, and clear the sump hole.
3. Remove food from the drain area and check for broken glass or labels.
4. Wipe the door gasket with a cloth and a little dish soap, including the folds where mildew hides.
5. Clean the spray arms. Remove them and clear the holes with a toothpick.
6. Wipe the door edges, the detergent dispenser and the bottom of the door.
7. Run a hot cycle with a cup of white vinegar in a bowl on the top rack, or use a dishwasher cleaner or citric acid.
8. Sprinkle baking soda on the floor of the empty tub and run a short hot cycle for freshness.

What the smell suggests

Smell	Likely source	What to do
Rotting food	Dirty filter and sump	Clean the filter and sump
Musty, mildew	Door gasket, damp interior	Wipe gasket, leave door ajar
Sewer or drain smell	Drain hose, air gap, disposal or trap	Clean the air gap, check the hose and trap
Rotten eggs	Bacteria in standing water, or drain gases	Clean thoroughly, check the drain
Plastic or burning	Overheating or a melted item	Stop and inspect, call a technician

If the smell is from the drain

A drain hose without a high loop lets sink water flow back into the dishwasher. A clogged air gap can leak, and a garbage disposal connection can hold rotting scraps. If your dishwasher smells bad even after a deep clean, check that the hose rises to the underside of the counter before it connects, clean the air gap, and run the disposal. If the kitchen sink also smells, the trap or branch drain may need cleaning.

Safe cleaners

White vinegar and citric acid dissolve scale and soap film, and baking soda absorbs odours. Do not mix bleach with vinegar or ammonia, because the fumes are dangerous. Many manufacturers advise against bleach in stainless-steel tubs, so check your manual. Commercial dishwasher cleaners are designed for a hot cycle in an empty machine.

Keeping it fresh

Scrape plates before loading, run the disposal first, clean the filter monthly, leave the door slightly open after a cycle, and run a cleaning cycle every month or two. Avoid long delays before running a full load, because food residue sours. Do not leave wet dishes sitting for days before a wash, since the water and food residue turn sour quickly.

When to call a professional

Call if the smell persists after cleaning, if you suspect a drain-line problem, or if the dishwasher leaks or does not drain.

Dishwasher smells bad: finding the source

A dishwasher smells bad when food, grease and water stay in places they should not. The most common spots are the filter, the seal around the door, and the area under the lower spray arm where small pieces of food collect. Start by removing the bottom rack and the filter, then clean each part by hand with warm water and a little dish soap.

Run an empty hot cycle with a cup of white vinegar placed on the top rack. Vinegar cuts through the film that causes odours. Wipe the door seal, which can trap moisture and food. If the smell is like sewage, check the drain hose and the connection to the sink or disposal, since a blocked drain can send bad air back into the machine.

A dishwasher smells bad most often when the filter has not been cleaned in months. If a dishwasher smells bad even after cleaning, check the drain hose for kinks.

Related reading

• Dishwasher Not Draining? 8 Checks Before You Call a Repair Pro
• Dishwasher Water Backing Up Into Sink: Causes and Fixes
• How to Get Rid of Garbage Disposal Smell: 6 Fixes That Work
• Why Is My Dishwasher Leaking? 9 Sources and How to Fix Them

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