Your washing machine is the only appliance in the house expected to come out clean at the end of every cycle without ever being cleaned itself. It doesn't work that way. Microbiologist Dr Charles Gerba of the University of Arizona has spent years sampling domestic machines, and his finding is blunt: a load of washing transfers bacteria between garments, and a machine that only ever runs cold cycles never gets hot enough to reset itself.
If your clean laundry smells faintly of damp even after a full cycle, the machine is the source — not the detergent, and not the clothes.
Quick Answer: Wipe the door seal with hot soapy water, soak the detergent drawer, and clear the pump filter (front loaders only). Then run an empty cycle at 60°C or higher with an approved machine cleaner or 250 ml of white vinegar — never both, and never with bleach in the same cycle. Repeat monthly. Between washes, leave the door and drawer ajar so the drum dries.
Why Washing Machines Start to Smell
Three changes to how Australians wash have made this a far more common problem than it was twenty years ago.
Cold washing. Most households now wash at 20–30°C to save energy, which is genuinely good for the power bill and for coloured fabrics. It is also comfortably below the temperature at which mould and bacteria die off, so nothing in a cold cycle resets the drum.
Front loaders. They use roughly half the water of a top loader, which is why they dominate new sales. Less water means less flushing, and the airtight rubber door gasket that makes them efficient also creates a permanently damp fold that never dries out.
Too much detergent. Excess detergent and liquid fabric softener don't rinse away completely. They leave a soft, greasy residue on the drum, the drawer and the hoses — and that residue is what the mould actually feeds on. The smell is the biofilm, not the water.
Ashley Iredale, formerly Head of Whitegoods at CHOICE Australia, is direct about the two habits that cause most of it: overdosing detergent, and closing the door the moment the cycle ends.
What You'll Need
White distilled vinegar (5% acidity) or a proprietary washing machine cleaner — pick one, not both
Hot water and dish soap
A microfibre cloth
An old toothbrush
A shallow tray or baking dish (for the pump filter)
A towel for the floor
⚠️ Safety note: Never combine bleach with vinegar, or with any acidic or ammonia-based cleaner. The reaction releases chlorine gas. The Washington State Department of Health treats this as a genuine household poisoning risk, not a theoretical one. If you use bleach in one cycle, run a full rinse before using anything else.
How to Clean a Front Loader
Front loaders need all four steps. Skipping the pump filter is the most common reason a machine still smells after a "clean".
Step 1: Clean the Door Seal
Pull the rubber gasket gently back with your fingers and look into the fold at the bottom. This is where black spotting starts, and it is almost always worse than it looks from the outside.
Wipe the whole fold with a cloth wrung out in hot soapy water, working right around the circumference. Use the toothbrush on the grey or black patches. Dry it completely with a fresh cloth — leaving it damp undoes the work.
If the mould has stained the rubber rather than sitting on it, Better Health Victoria recommends a diluted bleach solution on hard, non-porous surfaces. Ventilate the room, wear gloves, and rinse thoroughly afterwards.
Step 2: Soak the Detergent Drawer
Most drawers release with a firm pull plus a press on a small tab inside the cavity — check your manual if it resists. Soak it in hot soapy water for 15 minutes, then scrub the corners and the underside of the siphon cap with the toothbrush.
While it's out, reach into the empty cavity with a cloth. The roof of that cavity collects a surprising amount of softener sludge that never gets seen.
Step 3: Clear the Pump Filter
This is the step almost everyone skips. Behind the small flap at the bottom front of the machine sits the drain pump filter, and it catches coins, hair clips, tissue and lint.
Put the towel down and hold the tray against the machine — there will be water, often more than you expect. Unscrew the cap slowly, drain it, then pull the filter out and rinse it under the tap. Clear the housing with a finger, screw the cap back in firmly, and run a short rinse to check for leaks.
How often? Every three months for an average household. Monthly if you wash pet bedding or heavily linted towels.
Step 4: Run a Hot Maintenance Cycle
With the drum empty, add either 250 ml of white vinegar to the drum, or a proprietary machine cleaner following the packet directions. Run the longest, hottest cycle your machine offers — 60°C at minimum, 90°C if you have it.
Do not add bicarb soda at the same time as vinegar. As Dr Nathan Kilah, Senior Lecturer in Chemistry at the University of Tasmania, explains, the two neutralise each other on contact — the fizz is the reaction spending itself, and what's left is mostly salty water. Use one or the other.
When the cycle finishes, wipe the drum and the door glass dry and leave the door open.
How to Clean a Top Loader
Top loaders have no door gasket and no pump filter, which removes the two worst problem areas. They have a different one: the space between the drum and the outer tub, which you cannot reach.
Fill the drum with the hottest water your machine will draw, on the largest load setting.
Add 500 ml of white vinegar (top loaders hold far more water than front loaders, so the dose is larger).
Pause the cycle once it has agitated for a minute, and leave it to soak for an hour.
Restart and let it drain, then run a second rinse cycle empty.
Wipe the lid, the rim and the underside of the lid — mould collects on the lid seam where condensation runs down.
Many top loaders also have a small lint filter inside the drum or clipped to the agitator. If yours does, pull it out and rinse it.
The Two Habits That Actually Prevent It
Everything above is remedial. These two are preventive, and between them they stop most machines from ever smelling again.
Leave the door and the detergent drawer ajar. Not open — ajar is enough for airflow. A drum that dries between washes cannot grow biofilm. This one habit does more than any cleaning product.
Use less detergent than you think. Australian machines are efficient and Australian water is soft to moderately hard in most capital cities, so the dose on the bottle is generous for local conditions. Halve it for a normal load. If your clothes come out stiff or your machine over-foams, you were using too much.
Two supporting habits help: run one hot wash a fortnight (towels or bedding at 60°C serves the purpose and does the same job for dust mites, per Better Health Channel Victoria), and take the washing out promptly. A finished load left in a closed drum overnight re-seeds everything you just cleaned.
How Often to Clean a Washing Machine
Task | Front loader | Top loader |
|---|---|---|
Wipe the door seal | Weekly | n/a |
Detergent drawer | Monthly | Monthly |
Hot maintenance cycle | Monthly | Monthly |
Pump filter | Every 3 months | n/a |
Lint filter | n/a | Monthly |
Households that wash daily, wash pet bedding, or run mostly cold cycles should move to the shorter end of each interval.
Frequently Asked Questions
Q: Why does my washing machine smell even after cleaning it?
Almost always the pump filter or the door seal fold — the two places a maintenance cycle cannot reach. Water sitting in a blocked filter will re-scent every load no matter how many empty hot cycles you run. Clear the filter by hand first, then run the cycle.
Q: Can I use vinegar in my washing machine?
Occasionally, yes — a monthly maintenance cycle with 250 ml is fine and widely recommended. Several manufacturers advise against using it every wash, because sustained acid exposure can shorten the life of rubber seals and hoses. Treat it as a monthly reset, not a laundry additive.
Q: Should I use bleach or vinegar to clean my washing machine?
Either, never together, and never in consecutive cycles without a rinse between. Bleach is better on visible black mould staining in the rubber seal; vinegar is better on detergent residue and odour. Whichever you choose, run one empty rinse afterwards before washing clothes.
Q: How do I clean a washing machine that smells of mould?
Do all four front loader steps in order — seal, drawer, pump filter, hot cycle — rather than only the hot cycle. Then leave the door ajar permanently. If a musty smell survives two monthly rounds of that, the biofilm has reached the internal hoses and a technician's service is the realistic fix.
Q: Is a hot wash bad for my energy bill?
One 60°C cycle a fortnight is a rounding error against the cost of replacing a machine early or re-washing smelly loads. Keep everyday washing cold — the hot cycle is maintenance, not routine.
Q: Do I need to clean a new washing machine?
Yes, on the same schedule. Biofilm establishes in a matter of months in a machine that only runs cold cycles, and a new machine with the door kept shut is no more protected than an old one.
