How to Clean a Moldy Dishwasher: Remove Black Mold From Seals, Racks & Filter

Black specks along the door seal, a fuzzy line on the rack rails, a musty smell every time you open the door: mold loves dishwashers because they stay warm, wet and closed. Here’s how to clean a moldy dishwasher in short: scrub the mold off the door gasket, rack rails and filter with a baking soda paste and white vinegar, using a brush on flat surfaces and strips of a non-scratch scouring pad on the rails, then rinse and run a hot cycle and leave the door open to dry.

The tricky part is the dish racks. A regular scrub brush slides right off the round rails and barely touches the mold. Below, the Repairior editorial team shows the technique that actually works on rails and tines, plus which cleaners are safe, whether dishwasher mold is dangerous, and how to keep it from coming back.

Where Mold Grows in a Dishwasher

Mold needs moisture, food and little airflow. A closed dishwasher has all three. These are the spots to check first:

Area	Why mold grows there	How hard to clean
Door gasket (rubber seal)	Traps moisture and food film; never reached by the spray	Easy with a brush
Rack rails and tines	Small round surfaces stay wet; coating has tiny cracks	Hard with a brush; easy with scouring strips
Bottom lip of the door	Water and debris collect in the hinge fold	Medium
Filter and sump	Constant water and food scraps	Easy once removed
Utensil basket	Corners stay damp	Easy
Spray arms and drain hose	Water sits inside between cycles	Medium to hard

Black, Pink and White Mold in a Dishwasher: What They Are

• Black or dark green spots are typically mold colonies that grow on gaskets, rails and corners. They’re the most common.
• Pink or orange slime is usually not mold at all but a bacteria (often Serratia) that thrives on soap and mineral film. It cleans off the same way and tends to return when the dishwasher stays damp.
• White fuzzy growth is mold; a white chalky film is usually hard water scale instead, which wipes off with vinegar.

Is Mold in a Dishwasher Dangerous?

For most healthy people, a small amount of dishwasher mold is a nuisance rather than an emergency, but it’s worth removing promptly. The U.S. EPA and CDC note that mold can trigger allergy symptoms, irritation and asthma attacks, and people with weakened immune systems or lung conditions are more sensitive. Mold can also transfer to dishes that touch it and makes everything smell musty. Clean it as soon as you see it, and wear gloves while you do.

What You’ll Need

• Rubber gloves, and a mask if you’re sensitive to mold
• Baking soda
• White vinegar in a spray bottle
• A stiff toothbrush or small scrub brush
• A non-scratch scouring pad and scissors
• Microfiber cloths or old towels
• Optional: 3% hydrogen peroxide, or a dishwasher cleaner tablet

Which Cleaners Are Safe for Dishwasher Mold?

Cleaner	Good for	Cautions
Baking soda paste	Gentle scrubbing grit; lifts grime and odor	Rinse well so no residue is left
White vinegar	Kills many common household molds; removes mineral film	Don’t use daily; never mix with bleach
3% hydrogen peroxide	Spot-treating stubborn stains on seals	Apply separately from vinegar, rinse after
Diluted chlorine bleach	Heavy mold on plastic tubs, if your manual allows it	Avoid on stainless steel interiors; never mix with vinegar or ammonia
Dishwasher cleaner tablet	Final hot cycle to clean pipes, arms and tub	Follow package directions
Steel wool, wire brushes	Not recommended	Scratch rack coating and tub; cause rust

How to Clean a Moldy Dishwasher: Step by Step

Step 1: Protect yourself and empty the dishwasher

Put on gloves (and a mask if mold bothers you), open a window or run the kitchen fan, and unload any dishes. If dishes have been sitting in a moldy dishwasher, rewash them once the machine is clean.

Step 2: Remove the racks, utensil basket and filter

Slide out both racks and the third rack if you have one. Lift out the utensil basket. Twist out the filter and mesh screen from the floor of the tub. You’ll clean these separately, and removing them gives you access to the walls and sump.

Step 3: Apply baking soda paste and vinegar

1. Mix baking soda with a little water into a thick paste.
2. Spread it over the visible mold on the gasket, door lip, rack rails and corners.
3. Spray white vinegar over the paste. It will fizz.
4. Let it sit for 10–15 minutes to soften the growth and loosen stains.

The fizz itself mostly helps lift grime; the vinegar is doing the antimicrobial work and the baking soda gives you gentle scrubbing grit.

Step 4: Scrub the door gasket and flat surfaces with a brush

A toothbrush or stiff scrub brush works well on flat and grooved areas. Work along the full length of the door gasket, getting into its folds, then the door edges, the bottom lip where the door hinges, and the corners of the tub. Pull the gasket gently away from its channel if it allows, since mold often hides behind it.

Step 5: Use scouring-pad strips on rack rails and tines

This is the step that makes the biggest difference. On round rails, brush bristles just slip around the bar and skim over the mold. Instead:

1. Cut a non-scratch scouring pad into strips about 1–2 inches wide. Cut one or two narrow strips as well for tight spaces.
2. Wrap a strip around the rail so half is on each side.
3. Hold one end in each hand and pull back and forth, like shoe-shining, while pressing down. A few strokes usually clears a moldy section.
4. Use the narrow strips between closely spaced wires where the wide strip won’t fit. They wear out and tear faster, so use the wide strip wherever you can.
5. For the tines (posts), fold a strip over the post and scrub up and down with your thumb.

Use only non-scratch pads. Steel wool or green heavy-duty pads can strip the vinyl or nylon coating on the racks, and exposed metal rusts quickly.

Step 6: Clean the filter, sump and utensil basket

• Soak the filter and screen in hot water with dish soap and about a cup of vinegar, then scrub inside and out with a toothbrush.
• Soak up any standing water in the sump with a towel and wipe the sump clean.
• Scrub the utensil basket corners and rinse.

For the full filter routine, see our guide on how to clean a dishwasher.

Step 7: Rinse or brush off all residue

Wipe every treated area with a damp cloth to remove the baking soda paste and loosened mold. Rinse the racks in the sink or with a sprayer. You don’t want gritty residue left on the gasket where it can keep the seal from closing properly.

Step 8: Spot-treat stubborn stains (optional)

If dark stains remain in the gasket after scrubbing, dab on 3% hydrogen peroxide, let it sit 10 minutes and wipe clean. Some staining in old rubber can be permanent even when the mold itself is gone. If your manual allows bleach on a plastic tub, use a diluted solution as a separate step, rinse thoroughly, and never combine it with vinegar.

Step 9: Reassemble and run a hot cleaning cycle

Lock the filter back in place, reinstall the racks and basket, and run the hottest cycle your dishwasher has (Sanitize, Heavy or Normal with high-temperature wash) with a dishwasher cleaner tablet in the detergent cup, or with a dishwasher-safe cup of white vinegar upright on the top rack. This flushes out any remaining residue and cleans the spray arms and plumbing you can’t reach.

Step 10: Let it dry completely

When the cycle ends, open the door and pull the racks out partway so air can circulate. Leave it open for several hours or overnight before using it again. Drying is what stops the mold from regrowing.

Brush vs. Scouring Strips: What Works Where

Surface	Best tool	Why
Door gasket and folds	Toothbrush	Bristles reach into grooves without tearing rubber
Flat door and tub surfaces	Scrub brush or non-scratch sponge	Even pressure on flat areas
Rack rails	Wide scouring-pad strip, pulled with both hands	Wraps the rail and scrubs all sides at once
Tight spots between wires	Narrow scouring-pad strip	Fits where a wide strip can’t
Rack tines	Strip folded over the post, thumb scrub	Pressure all the way around a short post
Spray arm holes	Pipe cleaner or toothpick	Clears trapped debris and growth

How to Prevent Mold in Your Dishwasher

• Leave the door cracked open after each cycle and when the dishwasher isn’t in use.
• Run it regularly. A dishwasher that sits closed for a week with dirty dishes is a mold incubator.
• Clean the filter monthly, or twice a month with daily use.
• Wipe the gasket and door lip every week or two.
• Run a cleaner cycle monthly on the hottest setting.
• Use heated dry or rinse aid so the tub dries faster.
• Scrape food scraps into the trash before loading.
• Check the drain hose loop so dirty water can’t flow back and sit in the tub.

Mold Keeps Coming Back? Check These

Sign	Possible cause	Fix
Water pools on the tub floor	Drain clog or failing drain pump	Clear the filter and drain; call a technician if it persists
Mold returns in a week	Door kept shut; tub never dries	Leave the door open; use heated dry
Musty smell from the drain	Mold in the drain hose or sump	Clean the sump; have the hose checked or replaced
Gasket cracked or hardened	Old seal traps moisture	Replace the door gasket
Rust spots on racks	Coating worn through	Repair with rack touch-up coating or replace the rack
Water under the dishwasher	Leak feeding hidden mold	Stop using it and call a technician

Find Dishwasher Repair Near You

If mold keeps returning because the dishwasher won’t drain, the gasket is worn or there’s a leak, a local appliance technician can fix the cause. Compare pros and request free quotes.

Browse dishwasher repair companies · Get free dishwasher repair quotes · Dishwasher repair service guide

Moldy Dishwasher: Frequently Asked Questions

How do you get mold out of a dishwasher?

Remove the racks and filter, coat moldy spots with baking soda paste, spray with white vinegar and wait 10–15 minutes. Scrub the seal with a toothbrush and the rack rails with scouring-pad strips, clean the filter, rinse off all residue, run the hottest cycle and leave the door open to dry.

What kills mold in a dishwasher?

White vinegar kills many common household molds, and a baking soda paste helps scrub it away. Hydrogen peroxide works for spot-treating stains, and diluted bleach can be used on plastic tubs if your manual allows it, never mixed with vinegar.

How do I get black mold off my dishwasher seal?

Apply a baking soda paste, spray with vinegar, wait 10–15 minutes and scrub the gasket with a toothbrush, including the folds and behind the seal. Wipe clean and dab any lingering stains with 3% hydrogen peroxide.

How do I clean mold off dishwasher racks?

Cut a non-scratch scouring pad into strips, wrap a strip around the rail and pull it back and forth with both hands while pressing down. Use a narrow strip for tight spots and fold a strip over each tine to scrub it with your thumb.

Is pink mold in a dishwasher dangerous?

Pink slime is usually a bacteria rather than mold. It’s generally not dangerous to healthy people but can irritate sensitive individuals. Clean it off the same way and keep the dishwasher dry between uses.

Can I still use a dishwasher with mold in it?

Clean it before using it again. Mold can transfer to dishes and causes musty odors. After a deep clean and a hot cycle, it’s safe to use.

Why does my dishwasher keep getting moldy?

The usual causes are keeping the door closed so the tub never dries, a dirty filter, food left in the sump, or a drain problem that leaves standing water. A worn gasket can also trap moisture.

Should I use bleach or vinegar for dishwasher mold?

Start with vinegar and baking soda; they’re safe on most interiors. Use diluted bleach only if your manual permits it, never on stainless steel tubs, and never in the same cleaning session as vinegar.

How often should I clean my dishwasher to prevent mold?

Wipe the seal and door lip every one to two weeks, clean the filter monthly and run a hot cleaner cycle monthly. Leave the door open after each load.

Related Guides

• How to Clean a Dishwasher
• Can I Put Bleach in My Dishwasher?
• How to Clean a KitchenAid Dishwasher
• Dishwasher Repair Houston
• Garbage Disposal Repair Houston
• How to Clean a GE Profile Self Cleaning Oven
• Appliance Repair Houston

Conclusion

Learning how to clean a moldy dishwasher comes down to the right tool for each surface and getting the machine dry afterward.

• Use baking soda paste and white vinegar to loosen mold, and let it sit before scrubbing.
• Brush the door gasket, door lip and flat surfaces; use scouring-pad strips pulled back and forth on rack rails and tines.
• Clean the filter and sump, rinse off all residue and run a hot cleaning cycle.
• Leave the door open to dry, and keep it cracked between uses to stop regrowth.
• If mold keeps returning because of drain or seal problems, get free quotes from a local technician.

About This Guide

Editorial policy

This guide was written by David C and reviewed by the Repairior Editorial Team using appliance manufacturer care instructions, U.S. EPA and CDC mold guidance and standard appliance service practice. Businesses cannot pay to be featured in our how-to content.

Content transparency

Cleaner recommendations vary by brand and tub material; always follow your owner’s manual where it differs. This guide is not medical advice. If you have health concerns about mold exposure, consult a healthcare professional. Repairior earns revenue from optional business plans, which do not affect this guide.

About the author

David C is part of the Repairior Editorial Team, which researches home appliance care and repair and works with local repair businesses across the US to help homeowners keep appliances clean, safe and running well.

Helpful official resources: EPA mold guidance, CDC mold and health and CPSC recalls.