Mold in Washing Machine: How to Clean It and Keep It Out

A washer is warm, wet and full of food for mold: detergent residue, fabric softener film, lint and body soil from clothes. Consumer Reports says front-loaders are prone to mold and mildew, two types of fungus that thrive in damp environments.

Bob Vila lists the usual causes of a smelly washer: mildew, plus any residues that may have been attached to clothing, as well as softener or detergent buildup. Consumer Reports adds that mold can develop in various parts of the washer, including the dispensers and the rubber gasket around the opening.

Texas laundry rooms don't help. Much of the state is humid, with the Gulf of Mexico serving as the primary source of moisture for eastern Texas, so a closed washer in a Houston or Beaumont laundry closet dries slowly.

Front-loaders get mold far more often than top-loaders. Here are Consumer Reports' 2025 survey numbers:

Table: Front load washer mold vs. top-loaders, by owner reports.

The reason is the door seal. ENERGY STAR explains that front-loading washers use airtight seals to prevent water from leaking while the machine is in use, and that when the machine is not in use, this seal can trap moisture in the machine and lead to mold. Consumer Reports says the gasket, which keeps water in during the wash, traps it after the cycle.

Front-loaders are still worth having for many people. ENERGY STAR says certified front-load washers use about 50% less energy and water than a top load agitator washer. They just need a bit more care.

The gasket (also called the door boot) is where most people first see black spots.

1. Unplug the washer and put on gloves.
2. Pull back the folds. Consumer Reports says to gently pull back the gasket, wipe it clean, then dry. Check for socks, hair ties and lint stuck inside the fold.
3. Clean the surface mold. Use a cloth with detergent and water, or a diluted bleach solution if the manufacturer allows it. The CDC's limit for household bleach cleaning is no more than 1 cup of household laundry bleach in 1 gallon of water. Pull the folds gently so you don't tear the rubber.
4. Dry it completely with a towel, then leave the door open.

Some dark stains soak into the rubber and won't come out even after the mold is killed. If the gasket is torn, leaking, or still smells after cleaning, check the owner's manual or call an appliance repair company about replacing it.

Never mix cleaners. The CDC warns never mix bleach with ammonia or other cleaners. Bob Vila adds that combining bleach and vinegar is very dangerous. Pick one or the other. Our vinegar vs. bleach guide explains the difference.

Once the gasket is done, clean the rest of the machine.

1. Run a cleaning cycle

Consumer Reports says to run the tub-clean feature regularly. If your washer doesn't have one, run the machine on the hottest water-temperature setting with a cup of bleach but no laundry. ENERGY STAR notes that some manufacturers recommend rinsing the washer each month by running a normal cycle with 1 cup of bleach. Always check your owner's manual first, since some brands specify their own cleaner or amounts.

Bob Vila suggests a top-loader may take more bleach (it says to add 4 cups of bleach to the drum) and to follow with a service wash, a cycle at the hottest setting with the drum empty to rinse.

2. Clean the dispensers

Pull out the detergent, bleach and softener drawers if they come out. Scrub them in hot soapy water with an old toothbrush, and wipe the cavity they slide into, where black gunk often collects. ENERGY STAR mentions wiping down the compartments to help reduce the risk of mold or mildew buildup.

3. Clean the drain pump filter

Many front-loaders have a small filter that catches lint and debris. Consumer Reports says it's often located behind a small door at the bottom-right or bottom-left of the washer and recommends cleaning the filter every couple of months. Put a towel and shallow pan down first, because water will come out. Bob Vila notes that the water, lint, and dirt trapped in the filter and tube can cause the washer to smell.

4. Top-loaders: clean the rim

Top-loaders get less mold, but not none. Consumer Reports says periodically wiping down the circular upper rim of the tub and agitator is a good idea. Bob Vila suggests paying special attention to the cracks and crevices around the doors where dirt tends to hide.

What about washer cleaner tablets?

Store-bought washer cleaners can work, but you may not need them. Consumer Reports suggests running the sanitary cycle, or a hot cycle with a bleach-containing washer cleaner, once a month. Plain household bleach used per your manual does the same basic job.

Table: How to prevent mold in a washer.

One safety note from ENERGY STAR on leaving the door open: make sure children do not climb into the machine while the door is open.

If your laundry room stays humid, a dehumidifier can help the whole space dry out. The EPA recommends keeping indoor humidity below 60 percent (ideally between 30 and 50 percent).

Sometimes a washer is clean and the laundry room still smells. Bob Vila says that if your washing machine smells like sewage, even after cleaning, the issue might be a clog in the drain standpipe. That's a plumber's job.

A leaking washer is a bigger concern. A slow leak from a hose, the door seal or the drain can soak the floor and the wall behind the machine without you noticing. Pull the washer out and look for:

• Soft, stained or warped flooring
• Mold on the drywall behind or beside the machine
• A musty smell that stays after the washer is cleaned

The EPA says to dry water-damaged areas and items within 24-48 hours to prevent mold growth. If mold is on the wall or floor, read our guides on mold on walls and mold smell in the house.

When to call a professional

Texas lets you handle small areas yourself. TDLR says areas of visible mold of less than 25 contiguous square feet can be cleaned up by people who are not licensed. A mold-stained gasket is well under that. Hidden mold in the wall or subfloor from a long-term leak may not be.

If you need help figuring out how far a leak has spread, start with a licensed mold testing company. If removal is needed, hire a separate licensed removal company: Texas law says a license holder may not perform both mold assessment and mold remediation on the same project. Our guide on why testing and removal are different companies explains why.

Find licensed mold testing companies in Houston or Austin, and mold removal companies in Dallas, Fort Worth or San Antonio. Browse all Texas cities, verify a license with our license check, and read how we verify companies.

Health

A moldy washer gasket is a nuisance for most people. The CDC says some people exposed to mold get a stuffy nose, sore throat, coughing or wheezing, burning eyes, or skin rash, and that people with asthma or mold allergies can react more strongly. A doctor, not a mold test, diagnoses mold-related illness. See our mold allergy guide.