How to Clean a Washing Machine and Keep It Smelling Fresh
There is a particular smell that tells you a washing machine has turned: sour, damp, faintly of wet dog. It creeps in under the detergent perfume until one day you pull out a "clean" towel and realise it smells worse than it did going in. The culprit is rarely your laundry. It is a build-up of detergent, softener, body oils and lint sitting in the parts of the machine that never rinse properly, staying damp between washes.
A half-hour session once a month, plus ten minutes here and there, is usually enough to keep the drum, seal, drawer and filter clean — and to stop the smell returning. The trick is not to wait until the laundry smells. Once the biofilm has taken hold, it can survive several hot washes and keep seeding the drum with spores. A little routine maintenance is far easier than rescuing a neglected machine.
Why the smell happens
Most washes now run at 30°C or 40°C, which is kind to fabrics but gentle on residue. Fats and detergent don't always flush away; they collect in the coolest, least-rinsed corners of the machine — the rubber door seal, the detergent drawer, the drain filter and the sump under the drum.
Add moisture and you get a biofilm: a slippery layer of bacteria and mould that produces the smell. Fabric softener makes it worse by leaving a waxy film that traps lint. So does overdosing detergent, because extra foam means less effective rinsing.
Modern machines can make the problem worse in two ways. They use less water, so there is less of a flush through the hidden channels, and they often have a horizontal drum that leaves a shallow pool in the sump. If you habitually wash cold, use liquid detergent and leave the door shut, you are creating the perfect conditions for a slow, smelly build-up.
Some warning signs are easy to miss: a faint musty note when you open the door, a slimy feel on the rubber seal, grey sludge in the detergent drawer, or towels that smell sour as soon as they get damp. If any of those sound familiar, it is time for a proper clean rather than another perfumed cycle.
Run a monthly hot clean
Once a month, run the machine empty on the hottest cycle it allows, or on its dedicated drum-clean programme if it has one. Keep it simple:
- Check the drum is empty — no stray socks or cloths left behind.
- Wipe round the inside with a damp cloth to lift visible lint and hair.
- Put a washing machine cleaner, or roughly 100g of soda crystals, straight into the drum. Not in the drawer.
- Select a hot wash — 60°C or above. Check the manual first if the machine is under warranty or has a coated drum.
- When it finishes, leave the door open until the drum is completely dry.
- If the machine has been neglected, run a second hot rinse cycle.
Do not add laundry to this cycle. The point is to give the empty drum, pipes and sump a long, hot flush. If your machine has a "tub clean" or "machine clean" setting, use it exactly as the manual describes. Avoid using bleach unless the manufacturer explicitly recommends it; bleach can damage rubber seals and hoses over time, and it does not remove the greasy film that feeds the smell. If you use vinegar, keep it to occasional maintenance and never mix it with bleach-based products.
The door seal is where most of the smell lives
On a front loader, the rubber gasket folds back on itself and hides a pocket of exactly the wrong things: lint, hair, tissue, slime. Pull the lip gently away from the drum and look inside. Most machines will show a grey paste that no amount of rinsing will shift on its own.
Wipe it out with warm soapy water, or a solution of equal parts white vinegar and water, working into the crease with an old toothbrush. Dry it with a cloth afterwards. Don't tug hard — the seal is meant to sit snugly, and a torn gasket means a leak.
Never mix vinegar or any other acid with bleach-based cleaners. The combination releases chlorine gas, which is genuinely dangerous in a small room. Rinse thoroughly and ventilate between different products.
If the seal is black with mould that won't budge, or feels stiff and cracked, replace it. New gaskets are widely available for popular models and are usually a straightforward fit.
The detergent drawer and the drain filter
Cleaning the drawer
Pull the drawer out — press the release tab, usually under the softener compartment, or check the manual for your model — and soak it in hot soapy water while you deal with the housing.
Scrub the housing with a small brush. The black or orange film that builds up on the roof of the compartment is often the source of a chemical, musty smell. Rinse, dry and refit.
Clearing the drain filter
Front loaders usually hide a filter behind a flap at the bottom front. It catches coins, hairpins, fluff and lint, and it will smell. Put down a towel and a shallow tray, unplug the machine, and expect a litre or two of grey water.
Many machines have a small drain tube beside the filter; pull the cap, let the water run into the tray, then unscrew the filter. Clean it under a running tap, pick out hair and lint, and check the impeller behind it for debris. Screw it back firmly, close the flap, and run a short rinse cycle to check for leaks. If the filter is broken or the cap will not seal, replace it — a slow drip there keeps the base of the machine damp and smelly.
If the smell keeps coming back
If you have cleaned the seal, drawer and filter, run a hot cycle and the smell still returns within a week or two, the problem is probably deeper in the machine. The sump, drain hose or internal pipework may be coated with biofilm that normal cycles cannot reach. In that case, repeat the hot clean with a dedicated washing machine cleaner, then run two empty hot rinses. Leave the door and drawer open between washes, and check that the drain hose is not kinked or pushed too far into the standpipe, which can let waste water siphon back.
It is also worth checking the drainage point. If the machine empties into a sink or standpipe that is partly blocked, dirty water can sit in the hose and ferment. A plumber or appliance engineer can clear the sump and hose properly. If the machine is old and the drum smells no matter what you do, the cost of a deep repair may not be worth it, but most machines respond well to a consistent cleaning routine.
Everyday habits that keep it fresh
Prevention is mostly about air, dosage and temperature. The machine does not need to be spotless after every wash; it needs to dry out and avoid a constant coating of soap and softener.
- After every wash: leave the door and detergent drawer ajar so air can circulate. Wipe the door seal with a dry cloth if it is wet.
- Use less detergent: dose for the load size and water hardness, not the cap. If clothes come out stiff or the drum feels slick, you are probably using too much.
- Skip or reduce fabric softener: it leaves a waxy residue that traps lint and feeds the smell. Use it sparingly, or try half the recommended amount.
- Run a hot wash occasionally: once every few weeks, wash towels, bedding or whites at 60°C or higher. This helps flush the machine as well as the laundry.
- Remove laundry promptly: clothes left in the drum overnight give bacteria a warm, damp place to grow.
- Check pockets: tissues, receipts and hair all break down into the lint that clogs the filter and seal.
- Clean the filter every three months: or more often if you wash pet bedding, gym kit or heavily soiled clothes.
- Do a monthly maintenance wash: put it in your calendar. Ten minutes of wiping and a hot empty cycle is cheaper than a repair call.
Follow that rhythm and the sour smell rarely gets a chance to start. The machine stays fresher, your laundry smells clean rather than perfumed, and you avoid that unpleasant moment when a supposedly clean towel tells you otherwise.
