Dishwasher Smells Bad? Here's How to Deep-Clean It
That musty, swampy smell when you open the dishwasher door is rotted food — trapped in the filter, the sump, the door gasket folds, and the drain hose. Here's the deep clean that actually fixes it, step by step. If the smell survives this, something's wrong mechanically — call A One Dishwasher Repair WA at (253) 549-3002.
Step 1: Clean the Filter (the Main Culprit)
Twist out the cylindrical filter assembly from the tub floor. You'll probably find a gray, slimy paste of old food — that's your smell. Scrub it with hot water, dish soap, and an old toothbrush. Rinse until the water runs clear. Do this monthly forever. Full walkthrough: how to clean your dishwasher filter.
Step 2: Scrub the Door Gasket
Pull back the rubber seal around the door and wipe the folds with a vinegar-dampened cloth. Black gunk lives in there. Also wipe the bottom edge of the door, which never gets washed by the spray.
Step 3: Clear the Spray Arms
Pop them off (most twist or unclip) and clear every hole with a toothpick. Rinse. A clogged arm leaves dirty water sitting in the tub — which stinks.
Step 4: Run the Vinegar Cycle
Place 2 cups of white vinegar in a dishwasher-safe bowl on the top rack. Run the hottest, longest cycle empty. Vinegar cuts grease and scale.
Step 5: Baking Soda Finish
Sprinkle 1 cup of baking soda across the tub floor. Run a short hot cycle. This deodorizes what the vinegar loosened.
Step 6: Check the Drain Hose
If the smell is like rotten eggs (sulfur), the drain hose may be holding stagnant water — no high loop, or a sag where water sits. That's a routing fix.
Prevention
- Scrape plates (don't rinse — modern detergent needs some grease to work, but no chunks)
- Clean the filter monthly
- Leave the door cracked after cycles so it dries
- Run a vinegar cycle monthly — especially with Washington's hard water
When Smell Means a Repair
Persistent rotten-egg smell after deep cleaning can mean a failing drain pump leaving dirty water in the sump, or a water heater issue (sulfur bacteria). If the smell won't die, call (253) 549-3002 — we'll find it.
Dishwasher Smell FAQs
Why does my dishwasher smell like rotten eggs?
Usually stagnant water in the drain hose or sump. Deep-clean per above; if it persists, the drain system needs service.
Will bleach fix dishwasher smell?
Don't use bleach — it damages stainless tubs and rubber seals. Vinegar + baking soda is safer and works better.
Or skip the chore entirely — our annual maintenance visit includes a full filter, sump, and gasket deep-clean.