Why Does My Dishwasher Smell Bad? Causes and Fixes

A smelly dishwasher is unpleasant — and it can transfer odors to your dishes. The good news is that dishwasher odors are almost always caused by buildup that can be cleaned. Here's why your dishwasher smells bad and how to fix it for good.

Why Dishwashers Develop Odors

Dishwashers are warm, moist environments — ideal conditions for bacteria, mold, and mildew to grow. Food particles, grease, and mineral deposits accumulate in the filter, spray arms, door gasket, and hidden corners of the machine over time. When these decompose, they produce unpleasant odors.

1. Dirty or Clogged Filter (Most Common)

The filter catches food particles during the wash cycle. When it's not cleaned regularly, trapped food decomposes and produces a foul, rotten smell.

Fix: Remove the filter (twist and lift from the bottom of the tub), rinse under warm water, and scrub with a soft brush. Clean every 1–3 months — more often if you run the dishwasher daily.

2. Food Debris Buildup Inside the Machine

Food particles accumulate in the spray arm holes, around the door gasket, in the corners of the tub, and under the bottom rack. Over time, this buildup decomposes and smells.

Fix: Run a monthly cleaning cycle with Affresh Dishwasher Cleaner Tablets (amzn.to/42P5MKQ). They power away odor-causing bacteria, limescale, and grime from the pump, tub, and hoses — 6 tablets for a 6-month supply. For ongoing freshness between cleaning cycles, use the Finish Freshener Lemon and Lime (amzn.to/4wzKM8m) — a dishwasher deodorizer that clips inside and releases fresh scent with every wash.

3. Dirty Door Gasket

The rubber door gasket is a prime spot for mold and mildew growth — it stays damp after every cycle and food residue collects in its folds.

Fix: Wipe the door gasket thoroughly with a damp cloth and a small amount of white vinegar or mild dish soap. Pay attention to the folds and creases. Do this monthly.

4. Standing Water in the Bottom

If the dishwasher isn't draining completely, standing water at the bottom becomes stagnant and smells. This is often caused by a clogged filter or drain.

Fix: Clean the filter and check the drain for blockages. If water consistently remains after the cycle, refer to the dishwasher not draining troubleshooting guide.

5. Garbage Disposal Odors

If your dishwasher drains into a garbage disposal, odors from the disposal can travel back into the dishwasher through the drain hose.

Fix: Clean the garbage disposal regularly. Run it with cold water and a few ice cubes, then flush with hot water and dish soap. Make sure the drain hose has a high loop or air gap to prevent backflow.

6. Mold or Mildew Growth

If the dishwasher is left closed when not in use, moisture trapped inside encourages mold and mildew growth — producing a musty smell.

Fix: Leave the dishwasher door slightly ajar between uses to allow air circulation and prevent moisture buildup. Run a cleaning cycle with Affresh tablets to kill existing mold and bacteria.

7. Sulfur or Egg Smell

A sulfur or rotten egg smell usually comes from bacteria in the drain line or from sulfur compounds in your water supply reacting with the heating element.

Fix: Run a hot cleaning cycle with Affresh tablets. If the smell persists, check your water supply — high sulfur content in well water may require a water treatment solution.

Complete Dishwasher Deodorizing Routine

1. Remove and clean the filter
2. Wipe down the door gasket with vinegar
3. Wipe the interior walls and spray arms
4. Place an Affresh tablet in the bottom of the empty tub and run a Hot cycle
5. Clip a Finish Freshener inside for ongoing freshness
6. Leave the door ajar after each use

Prevent Odors Going Forward

• Clean the filter every 1–3 months
• Run a monthly cleaning cycle with Affresh Dishwasher Cleaner Tablets (amzn.to/42P5MKQ)
• Use Finish Freshener Lemon and Lime (amzn.to/4wzKM8m) between cleaning cycles
• Leave the door slightly open between uses
• Scrape dishes before loading to reduce food debris
• Use quality detergent — the Finish Powerball Dishwasher Pods (amzn.to/3RE929j) clean effectively and help prevent residue buildup