How to Clean a Washing Machine: Mould, Smell and Drum (UK Guide)

Open your washing machine door right now and lean in. If there's a faint sour smell, a thin black-grey ring around the rubber seal, or sticky residue along the detergent drawer — you have a problem that's going onto your clothes every wash. The machine that's supposed to be cleaning your laundry is silently making it dirtier.

The good news: a fully grimy UK washing machine can be properly cleaned in around an hour with two ingredients you almost certainly already own — white vinegar and bicarbonate of soda. No expensive tablets, no chlorine bleach, no Mrs Hinch product haul.

This is the proper UK guide to cleaning a washing machine: drum, drawer, seal, filter, and the smell that won't go away.

Why washing machines get smelly and mouldy

Three things build up inside every washing machine over time:

• Detergent residue. Liquid detergents and fabric softeners leave a sticky alkaline film inside the drum, drawer, and door seal. The film traps fibres, dirt, and water.
• Limescale. Hard-water mineral deposits accumulate on the heating element and inside the drum. Rough surfaces give bacteria a foothold.
• Black mould. The constant warm-damp combination is paradise for Cladosporium and Aspergillus moulds, especially under the rubber door seal where water pools.

Once these three combine, you get the unmistakable musty smell, the grey ring around the seal, and clothes that don't quite smell fresh after washing. Modern UK households are particularly prone because cold-wash cycles (30°C and below, used for energy-saving) don't run hot enough to kill the bacteria.

How to clean a washing machine: the complete monthly routine

Total time: 60–90 minutes (mostly hands-off while cycles run). Frequency: once a month for normal use, once a fortnight in hard-water areas or if the machine is heavily used.

Step 1 — Empty the machine and inspect

Run an empty drum cycle? Don't. First open everything:

• Door: wipe out any standing water in the rubber seal with a dry cloth
• Detergent drawer: pull it out completely (most slide out with a small lever or button at the back)
• Filter: usually a small flap at the bottom-front of the machine. Lay an old towel down first — there will be a litre of stagnant water

You'll know immediately how bad things are. If the drawer has black slime or the seal has visible mould, you're in for the full deep clean. If it's just a faint smell, you can skip the manual scrub and go straight to the hot vinegar cycle.

Step 2 — Soak and scrub the detergent drawer

Fill the kitchen sink with very hot water and 250ml of white vinegar. Drop the detergent drawer in along with any removable inserts. Leave 30 minutes.

While it soaks, use an old toothbrush or a small bottle brush to clean the cavity where the drawer slides into the machine. There's almost always sticky brown residue at the back — this is the source of a lot of the smell. Spray with a 1:1 vinegar/water solution and scrub thoroughly. Wipe with a clean cloth.

After 30 min, scrub the drawer with the toothbrush, rinse with hot water, dry, and slide back in.

Step 3 — Clean the rubber door seal

The single dirtiest part of every washing machine. Pull the rubber gasket back gently — there's a fold where water and lint accumulate. You'll find:

• Black-grey mould (the worst smell offender)
• Lint, hair, coins, hairgrips, and other debris
• Slimy residue

To clean:

1. Wipe out solid debris with a dry cloth
2. Spray neat white vinegar generously inside the seal fold
3. Sprinkle bicarbonate of soda — you'll see fizzing where the residue is worst
4. Leave 10–15 minutes
5. Scrub with an old toothbrush, paying attention to the fold and the bottom of the seal where water pools
6. Wipe with a damp cloth to remove residue
7. Dry the entire seal with a clean cloth before closing the door

Stubborn black mould may need a second pass. If after two passes the mould is still ingrained in the rubber, the seal itself is permanently stained — functionally clean, cosmetically dark forever.

Step 4 — Clean the filter (most people skip this)

The filter (technically the pump filter or "lint trap") catches anything the drum doesn't dispose of: hair, lint, coins, fluff, the occasional bra wire. It's usually behind a small panel at the bottom-front of the machine. Some machines hide it inside the door frame.

1. Lay an old towel and a shallow bowl in front of the panel
2. Open the panel; you'll usually see a small drain hose plus a circular plastic cap
3. If your machine has a drain hose, point it into the bowl and uncap it — up to a litre of water will drain out
4. Once drained, unscrew the circular filter cap (turn anticlockwise)
5. Pull the filter out completely
6. Rinse under the hot tap, scrub with an old toothbrush to remove debris and slime
7. Wipe out the filter housing inside the machine with a damp cloth
8. Replace the filter (turn clockwise to lock), close the panel

If you've never cleaned the filter, expect the worst — the smell can be staggering, and you'll fish out things you didn't know you'd lost. This alone often fixes a smelly machine.

Step 5 — Run a hot vinegar cycle to clean the drum and pipes

With drawer cleaned, seal cleaned, filter cleaned — now you can clean the inside of the drum and the internal pipes.

1. Pour 500ml of white vinegar directly into the empty drum
2. Add 100g of bicarbonate of soda
3. Run the hottest cycle your machine offers (usually 90°C, sometimes labelled "drum clean" or "tub clean") on a long programme
4. Optional: add a second 250ml vinegar splash to the detergent drawer to flush the dispensing pipework

The vinegar dissolves limescale and detergent residue. The bicarbonate of soda neutralises odours. Hot water kills bacteria. After the cycle, leave the door open for 1–2 hours so the drum dries fully.

Cleaning a washing machine without vinegar

If you can't or won't use vinegar (some machines' rubber seals can degrade with frequent acidic exposure — check your manual), citric acid is the better alternative:

• Citric acid powder: 200g in the empty drum, run a 90°C cycle. Cleaner finish than vinegar, no smell during the cycle, gentler on rubber. About £3 for 500g from supermarket baking aisles or eBay.
• Soda crystals: 200g in the drum, 90°C cycle. More aggressive on grease and detergent residue but can damage some rubber over time.
• Branded products: Calgon, Dr Beckmann Service-it Deep Clean, Ecozone Forever Flush. All work, but cost 4–5x more than vinegar/citric acid for the same effect.

The ongoing maintenance routine (so you don't have to do this again)

What's causing your specific problem? A diagnostic

Common mistakes that make washing-machine smells worse

• Always closing the door tight after washes. Traps moisture in the drum and seal. Leave it ajar.
• Using too much detergent. Excess detergent doesn't rinse out, leaving a film that traps bacteria. Use the lowest dose your detergent recommends — usually less than the cap suggests.
• Always washing on cold (30°C and below). Saves energy but doesn't kill bacteria. Run at least one 60°C cycle a fortnight.
• Skipping the filter. Most people don't even know it exists. It's the single biggest source of smell.
• Using fabric softener every wash. The waxy coating left by liquid softener accelerates residue build-up. White vinegar in the rinse is a better alternative.
• Cleaning with bleach. Chlorine bleach degrades rubber seals over years and damages the stainless steel drum. Vinegar and bicarb do the same job without the damage.

Does TruWash help with washing machine cleaning?

Honestly, for the routine itself: no, vinegar and bicarbonate of soda are the right products. We do sell 5L bottles of distilled white vinegar if you'd like to bulk-buy — one bottle handles a year's worth of monthly machine cleans plus laundry softening.

What we can help with is preventing build-up in the first place. Our BioPure Laundry Sheets dissolve more cleanly than liquid detergents and don't leave the alkaline residue that accelerates build-up. They're also pH 6–7, which is gentler on the rubber seal than highly alkaline conventional detergents over time.

Frequently asked questions

How do I get rid of the smell from my washing machine?

Run a 90°C cycle with 500ml white vinegar and 100g bicarbonate of soda in an empty drum. Then leave the door ajar for 1–2 hours to dry. If the smell persists, clean the rubber seal manually and check the filter — both are common hidden sources.

Why does my washing machine smell after every wash?

Three usual reasons: (1) bacteria growing in the rubber seal, (2) old detergent residue in the drawer or pipework, or (3) a clogged filter. Address all three by following Steps 2–5 of the routine above. Usually fixed in one deep clean.

Will white vinegar damage my washing machine?

Used monthly at recommended doses, no. The main caveat is the rubber door seal — very frequent neat-vinegar exposure (multiple times a week) can degrade some rubbers over years. Monthly use at the doses in this guide is fine for every modern washing machine.

Can I use bleach to clean my washing machine?

You can, but it's the inferior choice. Chlorine bleach degrades rubber seals and the stainless steel drum over years, and it leaves residue that can transfer to clothes. Vinegar and bicarbonate of soda do the same job better.

How often should I clean my washing machine?

Hot vinegar cycle once a month, full deep clean (drawer + seal + filter + drum) every 6 months. In hard-water areas (most of southern England), bump everything to twice as often.

Why is there black mould around my washing machine door?

The rubber seal stays damp after every wash, especially if you close the door immediately. Mould loves warm + damp + dark. Manual scrub with vinegar + bicarb (Step 3), and leave the door ajar after every wash.

How do I clean my washing machine filter?

Find the small panel at the bottom-front of your machine. Drain the hose, unscrew the filter cap (anticlockwise), pull the filter out, rinse under hot water, scrub with a toothbrush, replace. Lay a towel down first — up to a litre of stagnant water comes out.

What's the best product to clean a washing machine?

Cheapest and most effective: 500ml white vinegar + 100g bicarbonate of soda + a 90°C cycle. Costs <£1. If you prefer no vinegar smell during the cycle, citric acid powder (200g) is the next best.

Why does my washing machine drum smell like sewage?

Almost always a blocked filter or drain hose — stagnant grey water sitting in the system. Clean the filter (Step 4) and check the drain hose isn't kinked. The smell usually clears within 1–2 cycles after.

Should I run a washing machine clean cycle empty or with clothes?

Empty. Clothes will absorb the vinegar and emerge slightly acidic-smelling (which fades) but more importantly, you want the cleaning agents reaching every surface of the drum and pipework, not being absorbed by fabric.

Got a washing-machine problem we haven't covered? Email us — family of three, no support script.