How to clean a dishwasher and get rid of the smell

Step by step

1. 1

   Remove the bottom rack and wipe out debris

   Slide out the lower rack. Pick out food scraps, glass chips and labels from the tub floor and around the drain, then wipe the bottom and the door edges with a damp cloth.

   Why: Food soil that falls off dishes collects at the bottom and decomposes, causing odors and poor cleaning.

2. 2

   Clean the filter

   Find the filter at the bottom center (many twist counterclockwise to release; your manual shows how). Rinse it under running water and brush off debris gently, without excessive force, then reinstall it so it locks in place.

   Why: A clogged manual-clean filter holds rotting food that gives off a strong odor, and it also reduces cleaning performance.

3. 3

   Clear the spray arms

   Spin the spray arms by hand and look at the small jets. Gently clear any blocked holes with a paper clip or tweezers.

   Why: Blocked jets leave parts of the load dirty and let food film build up.

4. 4

   Run a vinegar cycle

   Put 2 cups of white vinegar in an upright glass measuring cup on the lower rack. Run a normal cycle with no detergent and no dishes. One appliance maker uses heated dry; another says dry option off, so follow your manual.

   Why: The vinegar spreads through the wash and loosens mineral film and detergent buildup.

5. 5

   Finish with baking soda (optional)

   Sprinkle 1 cup of baking soda across the tub floor and run a short hot cycle.

   Why: Baking soda helps deodorize. Illinois Extension describes this vinegar-then-baking-soda routine as one appliance makers recommend.

6. 6

   Keep it fresh

   Scrape dishes rather than rinsing them, clean the filter regularly, and if you don't run the machine every day, run a rinse cycle on a partial load. Use a dishwasher cleaner about monthly if your manual suggests it.

   Why: Food left sitting in a warm, closed, humid tub for days is what starts the smell.

Why a dishwasher smells bad

The usual cause is food soil decomposing in the filter, the sump under it and the bottom of the tub. A manual-clean filter that's never been cleaned is the most common culprit. Dishes left for days in a closed, warm, damp machine add to it, and plastic tubs can hold odors.

Other causes to check: standing water in the bottom means the drain or filter is clogged, and it smells quickly. A sewage smell rather than a food smell can point to a problem in the household drain or air gap, which is a plumbing issue rather than a cleaning one.

What the tub is made of: stainless steel or plastic, with a rubber door gasket and plastic spray arms. Abrasive pads and concentrated or abrasive cleaners can harm the finish, so the interior is cleaned with damp cloths, soft brushes and cycles rather than scrubbing.

How to remove mold from a dishwasher

Mold and mildew grow where water and food film sit undisturbed: the folds of the door gasket, the bottom edge of the door, and around the filter. One appliance maker's instructions: mix 1/2 cup of chlorine bleach in 3 cups of water, clean the gasket or interior with a cloth or sponge, then run a rinse cycle to remove the leftover cleaner before the next use. It also warns against abrasive or concentrated cleaners.

On a stainless steel tub, keep bleach contact short and rinse thoroughly, because bleach left on stainless steel can corrode it. Never do the bleach step in the same session as a vinegar cycle, and never with ammonia: see what never to mix. If black spots return quickly, look for the cause: standing water, a dirty filter or a machine left closed and damp for long stretches.

White film and spots: hard water, not dirt

A cloudy white film on the tub and glasses is mineral scale from hard water. The fix is in how you run the machine: water hot enough at the dishwasher (one appliance maker says at least 120°F; the American Cleaning Institute says not lower than 130°F), enough automatic dishwasher detergent for your water hardness, and a rinse aid so water sheets off. A vinegar cycle or a dishwasher cleaner removes existing scale. Very hard water (more than about 10.5 grains per gallon) may need a water softener. For mineral deposits elsewhere, see hard water stains.

By situation

Dishwasher smells like rotten food

Clean the filter and the area under it first, then wipe the door seal and tub bottom and run a vinegar cycle. If the smell is back within days, check that the machine drains fully and that you're running it often enough.

Dishwasher smells like sewage

That points to the household drain or the air gap, not food soil, so cleaning the machine won't fix it. Have a plumber check the drain connection if it persists.

Standing water in the bottom

Clean the filter and check for debris in the sump. If water still won't drain after a cycle, the drain hose or pump needs attention per the manual or a technician.

Dish soap went in by mistake

The American Cleaning Institute's advice: take the dishes out, scoop out the suds, splash cool water in to rinse the suds down, and run an empty rinse cycle. Smother any overflow suds with a towel.

Plastic tub

Plastic tubs can hold odors. Regular filter cleaning and monthly cleaner or vinegar cycles keep it fresher; skip abrasive pads.

What not to do

• Don't use hand dishwashing liquid, laundry detergent, baking soda, borax or vinegar in place of dishwasher detergent. Other soaps make too many suds and can overflow; substitutes clean poorly and can damage items or the machine.
• Don't use abrasive pads or concentrated cleaners on the interior. They can harm the finish of the tub and racks.
• Don't mix bleach with vinegar, ammonia or dishwasher cleaners. Bleach with acids or ammonia releases toxic gases.
• Don't pre-rinse dishes heavily. One appliance maker says scrape but don't rinse: clean-looking dishes can make the soil sensor choose a lighter cycle.

Other methods that work

Dishwasher cleaner product

Formulated to break down limescale, grease and detergent buildup. Run it in an empty cycle per the label; some makers suggest monthly.

Caution: Use one product at a time, and don't combine it with bleach.

Smaller vinegar dose

Amounts differ by maker: one suggests about 1 ounce of vinegar in a small bowl on the lower basket with the standard cycle, rather than 2 cups.

Caution: Follow your own manual where it gives an amount.

Stain still there?

Still smells after a vinegar cycle

The source is probably still in the filter, sump or door gasket. Remove and scrub the filter, wipe the gasket folds, and check for standing water.

Dishes come out gritty or dirty

Clean the filter and clear the spray-arm jets, load so the arms can spin freely, and check water temperature and detergent amount.

Cloudy glasses after cleaning

That's usually hard water. Add rinse aid, use more detergent if your water is hard, and run a vinegar or cleaner cycle.

Safety

• Store dishwasher detergent out of children's reach, not under the sink.
• Wear gloves and ventilate when using bleach on mold, and rinse it out with a cycle before the next load.

Never mix cleaning products; see chemicals you must never combine.

Questions

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