How to Clean a Dishwasher to Stop Odors and Buildup

How to Remove and Scrub the Removable Mesh Food Trap

Most modern dishwashers run quietly because manufacturers replaced loud, internal food grinders with a manual filter. This removable mesh food trap sits at the bottom of your wash tub and catches stray rice, meat gristle, coffee grounds, and cheese before they can enter the drain pump. When that screen fills up with old food scraps, water cannot circulate with full force, and decaying particles wash back over your plates as cloudy film or gritty specks. Cleaning this filter by hand is the single most effective way to eliminate sour smells and restore your machine's washing power.

1. Slide the lower dish rack all the way out of the machine. This gives you clear access to the bottom floor of the wash tub without wire dish tines blocking your hands or scraping your arms.
2. Locate the round filter cylinder in the floor of the tub. You will find it in the low point of the tub floor, usually set slightly off-center beneath the lower spinning water arm.
3. Turn the cylindrical filter a quarter turn counterclockwise to unlock it. Most modern brands use a simple twist-lock mechanism marked with small directional arrows on the plastic rim so you can release the filter without tools.
4. Pull the cylindrical mesh trap straight up out of the sump hole. Lifting the central cylinder unlocks the flat metal plate that rests around it, allowing you to lift both filter components out together.
5. Rinse the filter parts under hot running sink water. Hot tap water instantly softens hardened grease, dairy film, and sticky sauce residues clinging to the fine plastic and metal screens.
6. Scrub the mesh screens gently using a soft-bristle nylon brush and liquid dish soap. A gentle nylon brush clears stuck-on scale and slime from the tiny holes without tearing or stretching the delicate screen fabric.
7. Reach into the open drain hole at the bottom of the tub with a gloved hand. Check the shallow well for hard debris such as broken glass shards, lemon seeds, olive pits, or plastic wrappers that could jam the drain pump impeller.
8. Seat the flat plate and twist the cylindrical filter clockwise until it clicks into its locked position. Locking the assembly tightly prevents loose food grit from slipping around the edges and clogging your machine's internal spray nozzles during future wash cycles.

Checking the Rubber Door Seals and Spinning Water Arms

While the center of the tub gets drenched with hot water and detergent during every cycle, water spray never makes direct contact with the outer perimeter of the door. Food splatter, grease, and soap scum accumulate around the edges, where they sit in a warm, humid environment. Over time, this dark rim becomes a breeding ground for black mold and sour odors. If you notice damp mildew spreading to other moisture-prone spots in your home, using a dedicated shower cleaner for mold can keep your bathroom tile and caulk fresh as well, but your dishwasher rubber requires gentle, food-safe care.

Work through this checklist to clear hidden grime from your door gaskets and wash mechanisms:

• Peel back the flexible rubber door seal along the top and sides. Run a soft microfiber cloth dipped in warm water and mild dish soap along the inner groove to pull out dark sludge and trapped grease.
• Scrub the rigid rubber flap along the very bottom of the door. The bottom seal is the dirtiest spot in the machine because dirty rinse water splashes against it and drains down, leaving a thick layer of slimy food soil.
• Inspect the small spray holes on the spinning water arms. Inspect the upper and lower arms to confirm that tiny nozzle holes are not blocked by calcium crust, bits of plastic film, or fruit seeds.
• Clear clogged water nozzles with a wooden toothpick. Push a wooden toothpick or a plastic zip-tie into blocked holes to break up debris without gouging or widening the factory-sized spray openings.
• Spin the arms by hand to verify smooth movement. The arms should rotate easily without catching on heating elements or wobbling off their center mounting hubs.

Running an Empty Hot Cycle to Strip Grease and Mineral Buildup

Manual scrubbing takes care of physical debris, but your dishwasher also contains hidden internal plumbing lines, pump housings, and heating coils that you cannot reach by hand. In homes with hard water, dissolved calcium and magnesium react with heat to create a chalky white mineral buildup that blankets the heating element and coats water passages. Running a specialized hot cycle breaks down this chalky crust and dissolves stubborn animal fats clinging to internal hoses.

1. Run your kitchen sink faucet until the water flows hot. Dishwashers pull water directly from the hot water supply line under your sink, so purging cold water from the pipe ensures the wash cycle starts at peak cleaning temperature immediately.
2. Place an 8-ounce, dishwasher-safe bowl upright on the top rack and fill it with plain white vinegar. Keeping the vinegar in an upright bowl prevents the machine from pumping the acidic liquid straight down the drain during the initial 30-second pre-drain sequence, allowing it to mix gradually into the main hot wash.
3. Select your machine's hottest cycle option. Choose Heavy Duty, Pots and Pans, or Sanitize to raise the water temperature above 130 degrees Fahrenheit, which softens hardened animal fats and boosts the descaling action of the wash.
4. Turn off the heated dry setting before starting the machine. Letting the tub air-dry naturally saves electricity and prevents mineral-laden wash droplets from baking onto your stainless steel tub walls.
5. Allow the cycle to run completely without opening the door. Completing the full cycle ensures the acidic wash water circulates through every internal hose and flushes out through the drain line.
6. Crack the dishwasher door open two inches as soon as the cycle ends. Allowing trapped steam to vent into the kitchen prevents residual humidity from settling along the door edges, which keeps stale odors from returning.

Dishwasher Cleaning Myths and Damaging Chemicals to Avoid

Internet cleaning advice frequently recommends harsh household chemicals or fizzy home remedies that can shorten the lifespan of your appliance or ruin expensive components. Dishwashers rely on delicate balance: heating elements reach high temperatures, water pumps use flexible rubber seals, and tub walls are often made from corrosion-resistant steel. Using the wrong cleaning agent can void your manufacturer warranty or cause expensive kitchen leaks.

Keep these chemical rules and myth-busting facts in mind before pouring anything into your appliance:

• Never pour liquid chlorine bleach into a stainless steel dishwasher. Bleach chemically attacks stainless steel by stripping away the invisible chromium oxide film that shields the metal from rust, leading to permanent pitting, discoloration, and pinhole water leaks. Bleach is only safe in machines with all-plastic interior tubs.
• Do not mix white vinegar and baking soda together in the same cycle. Combining an acid (vinegar) with a base (baking soda) creates an exciting foaming reaction, but the chemical reaction instantly neutralizes both ingredients into salt water and harmless carbon dioxide gas, leaving you with zero grease-cutting or descaling power.
• Avoid using vinegar in every single wash cycle. While an occasional vinegar wash is excellent for cutting scale, continuous exposure to concentrated acetic acid can dry out and degrade certain soft rubber door seals, internal O-rings, and drain hoses over several years.
• Never add regular liquid hand dish soap into the dispenser. Even two drops of concentrated dish soap create an uncontrollable wall of thick suds that can blow past the rubber door seal, flood your kitchen floor, and trigger your machine's internal leak-detection flood sensor.

A Simple Monthly Maintenance Routine to Prevent Odors

Preventing foul dishwasher smells takes far less effort than clearing out months of neglected, rotten food waste. By practicing a few basic habits, you keep your machine running efficiently, reduce your water heating costs, and ensure your glassware comes out crystal clear without lingering cloudy films.

Adopt this simple maintenance rhythm to keep your machine in top shape:

• Scrape solid food into the trash before loading plates. You do not need to pre-rinse dishes under the tap, but scraping off solid items like bones, avocado skins, toothpicks, and bulk rice keeps your filter clear for weeks.
• Leave the machine door cracked open when the appliance is not in use. Keeping the latch open an inch allows fresh air to circulate through the dark tub, preventing anaerobic bacteria and musty mildew from taking hold.
• Pull and rinse the removable mesh food trap once a month. Inspect the screen under bright light to verify that all mesh openings are clear of hardened grease, calcium crust, and paper label fibers.
• Wipe the bottom door flap monthly with a damp cloth. A quick swipe across the bottom rubber lip stops sticky milk solids and grease splatter from developing into sour-smelling black slime.
• Run a high-heat cleaning cycle every 30 days. Running an empty cycle with an acid descaler clears grease buildup inside hidden pump lines before it can settle into stubborn blockages.

Choosing the Right Dishwasher Cleaner and Descaler Tablets

While vinegar works well for light maintenance, dedicated dishwasher cleaning and descaling tablets provide a much deeper clean for internal appliance parts. Commercial tablets contain concentrated, slow-dissolving cleaning agents and descaling compounds like citric acid that stay active across the entire wash cycle rather than washing away in the first rinse water. They dissolve stubborn grease plugs, strip away stubborn white chalky mineral buildup, and clean internal pump impellers that you cannot reach by hand.

When shopping for dishwasher cleaner tablets, check the product packaging to verify that the formula is safe for both stainless steel interiors and plastic tubs. Look for concentrated, septic-safe descaling tablets that target hard water mineral scale as well as sour food fats. Multi-packs that provide a 12-month supply make it easy to maintain a regular monthly cleaning habit, ensuring your machine circulates water at full pressure and leaves every dish clean.

1

GRIME LABS Dishwasher Cleaner Deodorizer Descaler Tablets, 24 pack Heavy

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• VC Score

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  8.3
• Brand
  GRIME LABS

Key specs2

Supply and Tablet Count

24 tablets (12-month supply)

Target Buildup

Formulated specifically for natural limescale removal and deodorizing internal dishwasher components during heavy-duty cleaning cycles.

Pros & cons32

Pros

• Includes 24 tablets to support regular maintenance across a full 12-month period
• Targets chalky mineral deposits directly with natural limescale remover action
• Combines internal deodorizing with heavy-duty cleaning to address sour tub odors

Cons

• Does not state an added scent, so it does not leave a perfumed fragrance behind
• Listing leaves tub material compatibility unconfirmed, requiring verification for stainless steel

2

Affresh Dishwasher Cleaner, Deep-Clean for All Dishwashers, 12 Month Supply

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  8.1
• Brand
  Affresh

Key specs2

Machine Compatibility

Affresh designates this deep-cleaning formula for use across all dishwasher models, regardless of manufacturer.

Maintenance Interval

12-month supply

Pros & cons32

Pros

• Specifically designated for deep cleaning across all dishwasher brands and machine models
• Provides a 12-month supply packaged for scheduled machine maintenance
• Designed to deep-clean hidden parts without requiring manual scrubbing of internal components

Cons

• Listing does not state the exact tablet count included in the 12-month package
• Does not specify whether the formula targets limescale or leaves an added fragrance

3

Dishwasher Cleaner Tablets - 24 Tablets (1-Year Supply) Lemon-Scented, Heavy

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  7.5
• Brand
  Bastion

Key specs2

Scent Profile

Lemon-scented

Supply and Application

• 24 individual descaler pods
• Provides a 1-year cleaning supply
• Aims at heavy-duty descaling and regular maintenance

Pros & cons32

Pros

• Contains an added lemon scent to leave a clean citrus smell after the wash cycle
• Provides 24 descaler pods to maintain machine performance over an entire year
• Formulated for heavy-duty descaling to dissolve hard water scale and residue

Cons

• Added lemon fragrance may not suit households sensitive to scented cleaners
• Listing does not state tub material safety, so users must verify stainless steel compatibility

Last update on 2026-10-26 / Affiliate links / Images, Product Titles, and Product Highlights from Amazon Product Advertising API

Frequently Asked Questions

Why does my dishwasher smell like rotten eggs or standing sewage?

A rotten egg or sulfur smell usually means rotting food waste has collected in the bottom drain sump, or your drain hose lacks a proper high loop under the sink. Without a high drain loop, dirty sink water can back up into the bottom of your dishwasher tub and sit stagnant. Remove the mesh filter, clear the drain well, and verify that your drain hose arches higher than the sink drain inlet to stop backflow.

Can I clean my dishwasher using baking soda by itself?

Yes, baking soda works well as a gentle deodorizer and mild abrasive when used on its own. Sprinkle one cup of baking soda across the floor of the empty dishwasher tub and run a short, hot wash cycle. The mild alkalinity of baking soda helps neutralize sour food odors and lifts greasy films from the tub walls without scratching plastic or metal.

How do I know if hard water is ruining my dishwasher performance?

Hard water leaves a distinctive white chalky mineral buildup on the heating element, dulls the stainless steel walls, and coats clear glassware in a cloudy white haze that does not wipe off easily. If glasses feel rough or cloudy after drying, calcium and magnesium minerals are coating the internal spray nozzles and reducing water pressure. Running an acid descaler tablet dissolves this rock-hard crust and restores full water circulation.

When should I stop cleaning and call a professional appliance repair technician?

You should call a professional technician if the machine fails to drain water after you have thoroughly cleared the filter and inspected the drain hose for kinks. A persistent pool of dirty water at the end of a cycle often points to a burned-out drain pump motor or a failed check valve. Stop operating the machine immediately and call a certified technician if you see water pooling under the kitchen cabinets, smell burning electrical wires, or hear loud metal grinding sounds during the wash.