How to Clean a Dishwasher Filter and Remove Odors

You open your dishwasher expecting clean, sparkling plates, but instead you get hit with a blast of sour, swampy steam. Even worse, your glassware comes out speckled with gritty residue. When a dishwasher stops cleaning properly or starts to smell bad, the culprit is almost always the filter system at the bottom of the tub. Modern dishwashers run quieter and use significantly less water than older models. To do this, manufacturers replaced noisy built-in food disposers with manual-clean filter assemblies. When you skip cleaning this component, trapped food scraps, grease, dairy solids, and detergent scum decompose in a warm, dark environment. Fortunately, clearing the filter and eliminating persistent odors takes less than twenty minutes and requires only basic household supplies. Quick Answer: How to Clean the Filter and Fix Odors To clean a dishwasher filter, slide out the bottom dish rack, locate the cylindrical filter at the base of the tub, and twist it a quarter-turn counterclockwise to release it. Pull out both the cylinder and the flat mesh plate beneath it. Rinse the parts under warm running tap water and gently scrub away trapped grease and mineral scale using a soft nylon dish brush and a few drops of grease-cutting liquid dish soap, such as Dawn. Wipe out any standing sludge from the sump opening at the bottom of the machine, reinsert the mesh plate, and twist the cylindrical filter back into place until it locks firmly. To banish lingering tub odors, place a dishwasher-safe bowl containing one cup of distilled white vinegar on the top rack and run a full cycle on the hottest setting without dishes or detergent. Follow with a light sprinkle of baking soda across the bottom of the tub and a short hot wash to neutralize any remaining acid and deodorize the interior.

Why Dishwashers Smell and Why Filters Get Clogged

Understanding how your appliance manages wastewater helps you prevent clogs and foul odors before they start. The Anatomy of Dishwasher Sludge Modern dishwashers recirculate wash water across multiple spray phases to conserve resources. The filter system stops food particles from being pumped back onto your dishes. Over several weeks, the filter captures a mixture of animal fats, cooking oils, tiny food fragments, and insoluble fibers. When warm wash cycles cool down, these fats solidify inside the ultra-fine mesh screen. Bacteria and mold feed on this trapped organic material, creating the classic sour, rotting odor that wafts into your kitchen whenever you crack open the door. The Garbage Disposal and Drain Line Connection In most American homes and rental units, the dishwasher drain hose routes directly under the kitchen sink, connecting either to the side of the garbage disposal or to a dedicated branch tailpiece before the P-trap. If the drain line lacks a high loop or an above-counter air gap, dirty sink wastewater and food waste from the disposal can siphon backward down the hose and pool in the dishwasher sump. If your machine smells like rotten eggs, sulfur, or standing sewer water, food matter rotting in the garbage disposal connection or a blocked air gap is frequently to blame. Hard Water and Detergent Buildup Across vast regions of the United States, tap water contains high concentrations of dissolved calcium and magnesium. When combined with concentrated dishwashing detergent, these minerals form insoluble scale that coats the filter mesh and the heating element. Mineral buildup narrows the filter openings, preventing water from draining freely. Food particles then become physically glued to the mesh by chalky limescale, speeding up odor development. Materials Needed for Filter Cleaning and Deodorizing Gather these standard household cleaning items before you start:

Liquid dish soap: A concentrated grease-cutting formula such as Dawn original works best to emulsify solidified cooking oils.

Soft-bristled brush: A worn nylon toothbrush or a soft nylon dish brush. Avoid stiff grout brushes or wire bristles, which tear mesh screens.

Distilled white vinegar: Standard 5 percent household white vinegar to dissolve mineral scale and cut sour odors.

Baking soda: Plain sodium bicarbonate to deodorize and freshen the tub.

Microfiber cleaning cloths: For wiping down the tub floor, door gaskets, and spray arms.

Flashlight or smartphone light: Essential for peering deep into the sump beneath the filter assembly.

Sponge: A non-scratch cellulose sponge to soak up murky standing water in the drain basin.

Screwdriver (model dependent): Most newer Whirlpool, Bosch, KitchenAid, and GE machines require no tools, but some older models use a Torx T15 or Phillips screw to secure the filter housing.

Step-by-Step Instructions to Clean the Filter and Tub Follow these sequential steps to thoroughly clean the filter, remove grease deposits, and eliminate stale odors from the entire machine.

Step 1: Clear the Appliance and Access the Filter

Start with an empty dishwasher. Pull the lower dish rack completely out of the machine and set it aside on a rug or towel to avoid scratching your kitchen floor. Look into the bottom basin of the stainless steel or plastic tub. You will find the cylindrical filter assembly located toward the back corner or directly beneath the center lower spray arm.

Step 2: Unlock and Remove the Filter Assembly

Most modern dishwashers feature a two-piece filtration system. Look for alignment arrows or padlock icons stamped into the plastic rim of the cylindrical upper filter. Turn the cylindrical filter a quarter-turn counterclockwise until it pops up slightly, then lift it straight out. Next, lift the flat metal or rigid plastic coarse filter plate that sits flush against the tub floor. In rental properties or older US appliances, you might find a single screw anchoring this plate. Remove the screw carefully and lift the plate out. Inspect the plastic rim of the cylindrical piece; many brands use an interior micro-mesh cylinder nested inside the outer cage. If yours separates, gently pull the two sections apart for a complete clean.

Step 3: Soak and Scrub the Filter Components

Bring the filter pieces to your kitchen sink. Rinse them under warm running water to flush away loose debris. Apply several drops of liquid dish soap directly to the mesh. Using your soft-bristled brush, scrub both the interior and exterior of the mesh cylinder using gentle, circular strokes. Do not press hard; fine plastic and woven metal screens bend or tear easily under heavy pressure. Pay special attention to the plastic seams where fats accumulate. If mineral scale has hardened onto the mesh, soak the components in a basin filled with equal parts warm water and distilled white vinegar for twenty minutes before brushing again. Rinse thoroughly with clean water.

Step 4: Clean the Sump and Surrounding Tub Basin

Take your flashlight and shine it directly down into the sump—the recessed well where the filter sits. You will likely see standing water, which is normal for keeping pump seals moist, but look closely for trapped items. Foreign objects like toothpicks, fruit labels, broken glass, olive pits, and bone splinters collect here and block pump impellers. Put on a pair of rubber cleaning gloves to protect your hands from potential glass shards. Remove any solid debris by hand. If the water inside the sump is thick, gray, or greasy, use your sponge to bail it out into a bucket. Wipe down the plastic walls of the sump with a microfiber cloth dampened with warm soapy water.

Step 5: Clean the Spray Arms and Door Gasket

Odors do not live only in the filter. Inspect the tiny water nozzles along the lower and upper spray arms. Hard water crust and tomato seeds frequently wedge inside these openings, reducing water pressure and leaving greasy deposits behind. Clear any clogged holes using a wooden toothpick. Next, examine the thick rubber gasket lining the perimeter of the dishwasher door, paying particular attention to the very bottom flap where the door hinges. This hidden crevice collects food grease and black mildew. Dip a microfiber cloth into warm water mixed with dish soap and wipe along the fold of the gasket until the cloth comes away clean.

Step 6: Reassemble the Filter Securely

Place the flat coarse filter plate back into position on the tub floor, ensuring it sits completely flush against the basin. Drop the cylindrical filter back into the center opening. Rotate the cylinder clockwise until you feel it click or see the alignment arrows line up precisely. Never operate your dishwasher if the filter is loose or misaligned. An unseated filter allows solid debris into the wash pump, which can destroy the motor seals or ruin the internal macerator.

Step 7: Run an Odor-Busting Sanitizing Cycle

Now that the physical grease traps are clean, treat the internal plumbing. Slide the bottom rack back into place. Fill a wide, dishwasher-safe glass or ceramic bowl with one cup of distilled white vinegar and set it upright in the center of the upper rack. Close the door and run a normal or heavy wash cycle on the highest temperature setting available, such as Sanitize or High Temp Wash. Do not add commercial detergent or dishes. The hot water will slowly disperse the acidic vinegar throughout the tub, dissolving limescale, melting residual grease from the internal pipes, and neutralizing sour odors. When the cycle finishes, open the door and let the tub air out for ten minutes. For a final freshness boost, sprinkle one cup of baking soda across the bottom of the tub and run a short, hot rinse cycle. Baking soda scrubs residual acidity and leaves a fresh scent.

Step 8: Clear the Air Gap or Garbage Disposal Drain

If your dishwasher still smells sour after running a clean cycle, your kitchen plumbing requires attention. If you have an above-counter air gap—a small chrome or plastic cylinder mounted next to your sink faucet—pop off the decorative cover. Unscrew or pull off the inner plastic cap and check for compacted food sludge or grease pushed up by the disposal. Clean it out with a bottle brush or bottle cleaner. If your home does not have an air gap, inspect the high loop under the sink. The dishwasher drain hose must loop up higher than the bottom of the sink basin before attaching to the disposal. If the hose droops down along the cabinet floor, food slurry from your sink drains directly into the dishwasher. Re-hang the hose securely near the underside of the countertop using a pipe bracket or zip tie.

What NOT to Do When Cleaning Your Dishwasher

Avoid these common mistakes that can void your appliance warranty or damage your home:

Do not use metal scouring pads or wire brushes: Steel wool, copper scrubbers, and brass wire brushes will shred the delicate mesh screen of the filter and leave tiny carbon particles behind that rust on stainless steel tub walls.

Do not pour boiling water directly into the tub: While hot tap water is safe, pouring a pot of rolling boiling water over plastic sumps and drain fittings can warp rubber seals and soften plastic housings.

Do not run the appliance without the filter in place: Running a load without the filter allows bones, seeds, and broken dish fragments into the pump assembly, resulting in expensive service repairs.

Do not use standard dish soap in the detergent dispenser: Never put liquid dish soap like Dawn into the dispenser cup for a cycle. It produces uncontrollable suds that pour out through the door seal and flood kitchen flooring.

Do not use excessive quantities of vinegar over long periods: Vinegar is an acid. While an occasional cup used quarterly is completely safe, using vinegar in every single wash cycle degrades delicate rubber gaskets and pump seals over time.

Safety and Material Warnings Protect your health and your home by reviewing these critical safety measures: Never Mix Bleach with Acids or Other Cleaners Never combine chlorine bleach with vinegar, ammonia, or commercial descalers. Mixing bleach with acids produces toxic chlorine and chloramine gases, which can cause severe respiratory damage or chemical burns. If you choose to sanitize a non-stainless tub with a bleach cycle, ensure the machine is thoroughly rinsed and completely free of vinegar residue first. Avoid Bleach on Stainless Steel Interiors If your dishwasher has a stainless steel interior tub or door liner, do not use chlorine bleach or cleaners containing sodium hypochlorite under any circumstances. Bleach attacks the protective chromium oxide layer on stainless steel, causing pitting, permanent dark discoloration, and microscopic corrosion that leads to leaks. Protect Surrounding Stone Countertops When pulling the vinegar bowl or wet, greasy filter out of the dishwasher, place them directly into the sink basin rather than onto adjacent countertops. Acidic cleaners like distilled white vinegar will quickly etch and dull natural stone surfaces, including marble, travertine, limestone, and unsealed granite. Beware of the Exposed Heating Element If you recently ran a drying cycle, the circular metal heating element at the base of the tub stays scalding hot for up to an hour. Always let the appliance cool completely before reaching inside to remove the filter to avoid severe contact burns. Maintenance Tips for a Fresher Dishwasher Prevent sludge from rebuilding by following these simple household maintenance habits:

Scrape food, but do not pre-rinse: Modern enzyme-based dishwasher detergents need residual food oils and starches to activate properly. Scrape large bones, toothpicks, and solid scraps into the trash, but leave minor residues for the detergent enzymes to break down.

Run the kitchen sink disposal before starting a wash: Turn on your cold tap and run the garbage disposal for ten seconds before pushing Start on your dishwasher. This clears the drain line and prevents food debris from backing up into the machine.

Leave the door slightly ajar: Trapping steam inside a sealed, dark appliance invites mildew and sour odors. Keep the door cracked open an inch or two between cycles to allow the interior tub and seals to dry thoroughly.

Clean the filter once a month: Mark your calendar for a monthly filter check. In homes that wash multiple loads daily or prepare grease-heavy meals, clean the mesh every two to three weeks.

Run a hot water purge at the sink: Turn on the kitchen faucet until hot water flows freely before starting your dishwasher cycle. This ensures the appliance fills with hot water right from the start, which properly dissolves detergent pods and melts cooking fats.

Frequently Asked Questions

How often should I clean my dishwasher filter?

For an average household running two to four loads a week, clean the filter once a month. If you only scrape dishes instead of rinsing them, or if you run the appliance daily, clean the filter every two weeks. If you live in an area with hard water, check the filter every few weeks to clear limescale deposits before they harden.

Where is the dishwasher filter located?

The filter sits in the bottom floor of the wash tub, usually recessed in a corner or directly below the lower spray arm. In most modern appliances from brands such as Bosch, Whirlpool, KitchenAid, Maytag, and Samsung, you access it by rolling out the lower rack. It appears as a round plastic cylinder with fine mesh windows.

Can I use bleach to deodorize my dishwasher?

You can use chlorine bleach to remove stubborn odors only if your dishwasher has a molded plastic interior. Never use bleach if your tub or door interior is made of stainless steel, as bleach permanently corrodes and pits the metal. Never mix bleach with vinegar or any other cleaning product.

Why does my dishwasher smell like rotten eggs or sewer gas?

A rotten egg odor usually points to trapped food decomposing in the drain hose, a dry P-trap, or backflow from the garbage disposal. Ensure your drain line has a high loop tied beneath the countertop to prevent dirty sink water from draining back into the machine. Running your garbage disposal with cold water and ice cubes can clear the source of the smell. Does hard water affect how often the filter needs cleaning? Yes. Hard water contains dissolved calcium and magnesium that precipitate out of the water under high wash temperatures. This mineral scale forms a white or yellowish crust over the filter mesh, trapping grease and blocking drainage. If you have hard water, soak your filter in white vinegar once a month to dissolve the scale.

What if my rental dishwasher does not have a removable filter?

Some older entry-level dishwashers feature a self-cleaning filter system equipped with a built-in macerator blade. These do not have a twist-out cylindrical screen. Instead, you will see a flat, perforated metal screen secured with screws at the bottom of the tub. You can clean this screen in place by scrubbing it with a soft brush and warm soapy water, then running an empty hot vinegar cycle to clear the internal lines.