How to Clean the Rubber Seal on Your Washing Machine

Quick Answer

To clean the rubber seal: wipe the inside of the folds with a damp cloth after every wash; remove visible mould with diluted white vinegar or a mould-specific spray; run a monthly drum clean cycle with an enzyme tablet to prevent organic residue accumulating in hard-to-reach areas. For pet owners, wipe the seal after every pet-related wash.

Why the Seal Is the #1 Cause of Machine Smell

If your machine smells musty, the seal is almost always the culprit. The EPDM rubber gasket traps water behind its fold after every cycle. Combine that standing water with detergent residue, fabric softener film, lint and skin cells, and you have an ideal environment for Cladosporium, Aspergillus and Penicillium — the three mould species most commonly found inside domestic washers. Given enough time, Stachybotrys (black mould) can colonise the darker recesses too.

What you're smelling isn't just mould spores, though. It's biofilm — a slimy matrix of bacteria, yeast and mould bonded to the rubber. Surface sprays and bleach kill the top layer, but the biofilm underneath keeps regrowing within days. That's why a quick wipe rarely fixes the problem for long, and why a full clean needs both a mechanical step (scrubbing the folds) and a chemical step (enzymes and percarbonate in a hot drum cycle) to break the film apart. For a wider look at odour causes, see why your washing machine smells bad and how to fix it.

Why the Rubber Seal Gets So Dirty

The rubber door seal (also called the door gasket) creates a watertight barrier between the drum and the outer door. Its folded design traps water, lint, hair, detergent residue, and organic matter inside the creases after every cycle. If the door is closed immediately after washing, this moisture creates the conditions for mould growth within 24–48 hours.

For households with pets, the seal is a collection point for pet hair, dander, and skin oils that pass through the drum. Over time this residue is redeposited onto the next load — contributing to clothes that smell of pet even after washing.

What Hides Inside the Seal

Pull back the rubber seal folds fully. Common findings:

• Grey or black mould spots — caused by moisture and organic material
• Accumulated pet hair and lint
• Solid detergent deposits — chalky white residue from powder detergent
• Fabric softener coating — sticky yellowish film
• Coins, tissue paper, and small items that got past the drum

Step-by-Step: Cleaning the Seal

Step 1: Wipe out the loose debris

Pull back the seal folds and use a dry cloth or paper towel to remove loose hair, lint, and debris from inside. Do this before adding any cleaning solution, or you'll just redistribute the mess.

Step 2: Clean with vinegar solution (general residue)

Mix equal parts white distilled vinegar and warm water. Dip a cloth and wipe thoroughly inside the seal folds. The mild acidity cuts through detergent film and light mould. Rinse with a clean damp cloth.

Step 3: Treat stubborn mould

For visible black mould spots: mix 1 tablespoon of bleach with 1 litre of warm water. Apply with a cloth, leave for 5 minutes, then wipe away and rinse thoroughly. Wear gloves. Ensure the drum door is open and the room is ventilated. The NHS notes that prolonged exposure to mould spores can aggravate asthma and allergies, so don't skip the gloves or ventilation.

Do not use bleach on the inside of the drum itself, and avoid getting bleach solution onto coloured fabrics.

Step 4: Run a drum clean cycle

After manually cleaning the seal, run a drum clean cycle with an enzyme tablet. This flushes the drain paths and removes the residue from inside the drum that feeds the seal build-up in the first place.

Preventing It Coming Back: Ventilation Habits

Cleaning the seal is reactive. Keeping it dry is what actually stops the mould returning. Three habits make the biggest difference:

• Leave the door ajar between washes so the drum and seal can air-dry. An hour is enough; overnight is better.
• Leave the detergent drawer open too — it's the second most common biofilm site.
• Dry-wipe the seal fold with a microfibre cloth after every wash. Ten seconds, and it prevents 90% of build-up.

Build these into a wider routine — our washing machine maintenance schedule covers filter cleans, hot service washes and descaling intervals.

Dirty Seal or Damaged Seal? How to Tell

Not every stained seal can be cleaned back to new. Check for these signs that the gasket needs replacing rather than scrubbing:

• Permanent black staining that doesn't fade after two or three deep cleans — mould has penetrated the rubber itself.
• Cracks, tears or pinholes along the fold — these cause slow leaks onto your floor.
• Hardened or brittle rubber that no longer flexes — the seal is failing and won't compress against the door glass.
• Musty smell that returns within 48 hours of a thorough clean — biofilm is embedded too deep to reach.

Replacing the Seal Yourself

A replacement door gasket typically costs £20–£50 for common UK brands (Bosch, Hotpoint, Samsung, LG), and the job takes around 30 minutes with a screwdriver and a pair of pliers once you've found the right part number on the inside of the door frame. YouTube has model-specific walkthroughs for almost every machine. If you'd rather not, an engineer call-out usually runs £80–£120 including the part. Either way, it's cheaper than replacing a washer that's started leaking through a split gasket — and far cheaper than the flooring repair underneath it.

For Pet Owners: Additional Steps

Pet hair accumulates in the seal folds faster than lint alone. After every load that includes pet bedding, blankets, or towels:

1. Check the seal and wipe out visible hair with a dry cloth
2. Leave the door ajar to allow the seal to dry
3. Run a drum clean cycle monthly (twice monthly if you wash pet items weekly)

Preventing Seal Build-Up

• Always leave the door ajar after a wash — seal dries, mould doesn't form
• Wipe the seal dry after the final wash of the day
• Use liquid detergent instead of powder — powder residue accumulates in the folds
• Don't overfill the drum — overfilling means less water circulation and more residue left on the seal

Related Reading

• Why Does My WM Smell Bad?
• How to Stop Pet Hair Clogging Your Filter
• WM Maintenance Schedule

Frequently Asked Questions

Is black mould on a washing machine seal dangerous?

The mould species most commonly found on washing machine seals (typically Aspergillus and Penicillium strains) can trigger allergic reactions and respiratory symptoms in sensitive individuals. It's worth addressing promptly, particularly in households with children, elderly occupants, or people with asthma.

When should I replace the rubber seal?

Replace the seal if you see cracks, tears, or splits in the rubber — these cause water leaks. Superficial mould that returns within days of cleaning, despite correct technique, may indicate the seal is too degraded to maintain and needs replacing. A replacement seal typically costs £20–£60 for the part.

Can a dirty rubber seal make clothes smell?

Yes. Mould and organic residue in the seal folds contaminate each wash with the odour compounds they produce. A machine that smells fine when empty but produces musty-smelling clothes almost always has seal and drum residue as the source.

How often should I clean the rubber seal?

Wipe the fold dry after every wash (ten seconds, no product needed), deep clean the seal with vinegar solution once a month, and treat visible mould as soon as you spot it rather than waiting for the monthly clean. Pet owners and households that wash heavy items (dog beds, gym kit) should add an extra mid-month seal wipe.

Can I clean a washing machine seal with baking soda?

Bicarbonate of soda (baking soda) mixed with water into a paste is safe on rubber and lifts light residue, but it won't shift mould that has embedded in the rubber or biofilm bonded deeper in the fold. For persistent black spots, dilute bleach or a mould spray does the job; for long-term prevention, keep the seal dry and run a monthly enzyme drum clean so residue never gets the chance to build up.