How to Clean a Front-Loading Washing Machine

By Priya — deep-clean specialist, Sydney.

I get called out to “broken” washing machines about twice a month, and nine times out of ten the machine isn’t broken at all. It’s just that the door seal has been quietly hosting a colony of black mould for the last two years, and the owner has finally noticed that their towels smell like a damp basement no matter what detergent they use. Last month I scraped 187 grams of black biofilm out of one Bosch Serie 6 — weighed it on the kitchen scales out of curiosity. The owner had been running her machine on cold every wash for four years.

The dishwasher-tablet hack you’ve seen on TikTok doesn’t work. It cleans the drum, sure, but it leaves the seal, the detergent drawer, the sump filter and the rubber gasket folds completely untouched — and that’s where 95% of the mould lives. Here’s the actual monthly routine I run on my own machine and recommend to every client.

The big Aussie-specific reason this matters: most front-loaders sold here are cold-fill only. American machines plumb into both hot and cold; ours mix hot internally with the heating element, which means the wash water often sits at 30–40°C — the perfect mould nursery. A monthly 90°C maintenance wash isn’t a nice-to-have, it’s the only thing that resets the bacterial load.

What you’ll need

• Sodium percarbonate (OxyClean, Bunnings $12 for 1 kg) — not chlorine bleach
• White vinegar — 2 L from Coles
• An old toothbrush and a microfibre cloth
• A small bucket and rubber gloves
• A torch (the seal folds are dark)
• Cotton buds for the detergent drawer corners
• A flathead screwdriver (for the sump filter cover)
• Old towels — there will be water

Step 1: Pull the detergent drawer all the way out

On Bosch and Samsung machines there’s a small tab inside the drawer — push it down and the whole drawer slides free. Miele uses a release button at the back. If you’ve never taken yours out, prepare yourself: the underside is usually black, slimy, and smells like a public bin in February. This is normal and it’s gross.

Soak the drawer in hot water with two scoops of sodium percarbonate for 30 minutes. Don’t use bleach — it eats the rubber seals on the drawer.

Step 2: Clean the drawer cavity

With the drawer out, shine your torch into the cavity. You’ll see the underside of the dispenser arm caked in detergent residue and mould. Mix 1 cup of vinegar with 1 cup of warm water and scrub the cavity with the toothbrush. Pay attention to the top of the cavity — gravity means most of the gunk sits up there.

Step 3: Fold back every door seal pleat

This is the bit everyone skips. The rubber gasket has 3–4 internal folds, and water pools in each one after every wash. Wear gloves. Pull each fold open, wipe with a microfibre cloth dampened with vinegar, and inspect with the torch. You’ll find hair, coins, lint, dead spiders, and that one missing AirPod tip from 2024. I’m not exaggerating about any of those.

Don’t use bleach on the seal. It’ll perish the rubber inside 12 months and a replacement gasket is $180 plus a service call. Vinegar and elbow grease only.

Step 4: Open the sump filter

Bottom-front of the machine, behind a small panel — pop it open with the flathead. Put your old towel down first. There’s always 200–500 mL of stagnant water in there. Unscrew the filter (anti-clockwise), pull it out, and clean off the fluff and coins. On a 5-year-old machine I usually find $3.40 in change.

Step 5: Run the 90°C maintenance wash

Empty drum. Pour 1 cup of sodium percarbonate directly into the drum (not the drawer). Set the machine to its hottest cotton cycle — 90°C on Bosch/Miele, “Sanitise” on Samsung, “Whites Plus” on Westinghouse. No spin pre-rinse. Run it.

This single cycle does more than 12 vinegar washes. The 90°C temperature denatures the biofilm proteins; the percarbonate releases hydrogen peroxide which oxidises what’s left. After this you’ve got a sterile drum.

Step 6: Run a vinegar rinse cycle

Once the hot cycle finishes, pour 500 mL of white vinegar into the drum and run a short cold rinse. This neutralises any percarbonate residue and descales the heating element. Aussie water is generally soft (Sydney) to moderate (Melbourne, Brisbane) — Adelaide and Perth water is harder and benefits more from monthly vinegar.

Step 7: Wipe the door glass and seal dry

Microfibre cloth, dry the inside of the door glass, dry every seal fold one more time. Reinstall the cleaned detergent drawer. Leave the door ajar from now on after every wash — this is the single biggest behaviour change you can make.

Step 8: Lock in the monthly habit

Set a recurring calendar reminder for the first Saturday of every month. The whole routine takes 15 minutes of hands-on time and a 2-hour wash cycle. If you skip a month you’ll know — the next towel load will tell you.

Step 9: Switch one wash a fortnight to 60°C

Even between maintenance washes, alternate your sheets and towels between cold and 60°C. Cold-only washing is what got you here. Modern detergents (Cold Power, OMO Sensitive) are formulated for cold but they don’t kill bacteria — only heat does that.

Step 10: Check the standpipe and hoses annually

Once a year, pull the machine out and check the drain hose for kinks and the standpipe for blockages. A partially blocked drain leaves dirty water in the sump between washes — that’s a separate mould source most people never address.

The Priya rule

If your towels smell like wet dog within 24 hours of washing, your machine is the problem, not your detergent. No amount of fabric softener will fix a contaminated drum — softener actually feeds the biofilm. Strip the seal, run the 90°C cycle, and leave the door open. Three steps, monthly, forever. Your nose will thank you and so will your $1,400 machine.

Got a cleaning routine that’s saved a piece of expensive kit? Send us a write-up.