How to Clean a Washing Machine

A washing machine that smells is not dirty in the ordinary sense. It has a film of detergent residue, fabric softener and body soil lining the parts you cannot see, and that film holds water and grows bacteria. The routine below removes it and stops it coming back.

The Monthly Maintenance Wash

Empty machine, hottest cycle available, longest programme. That combination matters: heat softens the film, and time gives the acid or cleaner a chance to work on it.

Two safety notes worth stating plainly: never mix bleach with vinegar, citric acid or any acidic cleaner, and never run a bleach cycle immediately after an acid one. And do not put a maintenance dose of anything into a machine with laundry in it.

The Door Seal, Where Front-Loaders Fail

On a front-loader the rubber bellows around the door has a lip designed to keep water inside the drum. That same lip holds a pool of water after every wash, and it is where black mould appears first.

• Peel the lip back gently and wipe all the way round with a damp cloth. This is the step most routines skip
• Look for trapped objects. Hairpins, coins and screws collect in the bottom of the fold and cut the rubber
• Dry the fold with a towel and leave the door ajar afterwards
• For established mould, use a cleaner the manufacturer permits, work it into the fold, leave it, then wipe. Do not scrub with anything abrasive: a torn bellows is a leak
• If the rubber is perished or split, that is a part rather than a cleaning job, and it sits in the cheaper half of our price book

The Detergent Drawer

Pull the drawer out completely; most release with a catch in the middle of the softener compartment. Take it to the sink, rinse it under hot water and brush out the softener channel, which is where a thick pink or grey sludge collects. Then look into the empty housing with a torch and clean the roof of it, where jets deliver water into the drawer: that surface is usually worse than the drawer itself.

Leave the drawer slightly open between washes. Along with leaving the door ajar, this is the single most effective habit for keeping a machine from smelling, and it costs nothing at all.

The Pump Filter

Behind a small hatch at the bottom front of most front-loaders sits the pump filter, and on many machines it has never been opened. It catches coins, buttons and hair before they reach the pump, and it also holds standing water that goes stale.

• Put a shallow tray and a towel down first. There is more water in there than you expect, and it comes out fast
• Some machines have a small drain tube beside the filter cap; use it to empty the water before unscrewing anything
• Unscrew the filter, clear it, rinse it, check the impeller behind it turns freely, and screw it back in firmly
• Do this every three to six months, and immediately if the machine starts draining slowly

Top-loaders often have no accessible filter of this kind; the equivalent maintenance is checking the drain hose and the standpipe, which is covered in why a washing machine will not drain.

Top-Loader or Front-Loader: What Changes

On a top-loader with a centre post, the agitator lifts off after one bolt under the fabric softener cap, and the underside of it plus the shaft below is a spot that never gets cleaned any other way. The removal sequence is in what an agitator is and how to take one out.

Why the Smell Happens at All

Three things combine. Modern machines wash cooler, so nothing reaches a temperature that clears organic film. Liquid detergent and fabric softener leave residue that is itself food for bacteria. And efficient machines use little water, so what residue there is gets rinsed away less thoroughly.

That is why the fix is a monthly hot cycle rather than a stronger product: heat plus acid removes the film, and nothing else does. It is also why over-dosing detergent makes the problem worse rather than better, and why a household that only ever runs quick cold cycles will have a smelly machine regardless of what it pours in. The humid-climate version of this problem is in why a washing machine smells musty.

Habits That Keep It Clean

• Leave the door and drawer ajar after every wash
• Take laundry out promptly. Wet clothes sitting in the drum for hours reseed everything you just cleaned
• Measure detergent to load size and water hardness, and use high-efficiency detergent in a high-efficiency machine
• Run one hot wash a month, with or without cleaner, even if all your laundry is cold
• Skip fabric softener occasionally, or replace it with a rinse-aid alternative: softener residue is a major contributor to the film
• Wipe the door glass and the frame when you wipe the seal, because that is where the smell is noticed first

When Cleaning Will Not Fix It

If the smell returns within a day or two of a thorough clean, water is standing somewhere rather than film remaining.

Across 170 completed washer repairs in our own book the median finished job came to $338, with the middle half between $255 and $411 and roughly three quarters under $400. Drain-side and seal work sit at the lower end of that. The full picture is in the washer repair cost database.

Getting Rid of an Established Smell

A machine that has been quietly building film for three years does not come right in one cycle, and that is the reason people conclude that cleaning does not work. The recovery routine is different from the maintenance one.

• Run three hot cycles over a week, not one. Use citric acid or a machine cleaner each time; the first cycle loosens, the later ones carry away
• Clean the filter between cycles. The film you have just released ends up there, and leaving it means putting it back into the next wash
• Wipe the seal after each hot cycle while the rubber is warm and the deposits are soft
• Expect black flakes on the first laundry loads afterwards. That is old biofilm leaving the outer tub, and it stops after a few washes
• Then change the habits, or you are simply scheduling the same job again next year

If three hot cycles plus a filter clean leave the smell intact, the film is somewhere the water no longer reaches, or standing water is being reintroduced. At that point a diagnosis is worth more than a fourth bottle of cleaner.

Hoses, Standpipes and the Things Behind the Machine

Twice a year, pull the machine forward far enough to look at what is behind it. Three things are worth checking and none of them take long.

The drain hose should sit in the standpipe loosely rather than being pushed deep into it, and the standpipe needs an air gap so the machine cannot siphon. A hose forced down as far as it will go is the most common cause of a drain smell that no amount of drum cleaning touches.

The fill hoses should be free of bulges, rust at the couplings and dampness at the connections. Rubber fill hoses have a service life and burst hoses are one of the most damaging failures a laundry room can have; braided stainless replacements are inexpensive.

The floor under and behind the machine should be dry. A slow leak leaves a tide mark long before it makes a puddle you notice, and a machine sitting on a damp floor rusts from the base upward.

The filter you clean as maintenance is the same one that stops a machine draining when it blocks: washer will not drain or spin.

Over-dosing detergent does more than leave residue: in a high-efficiency machine it foams out past the door seal and looks exactly like a leak. See washing machine leaking water.

If you want the reasoning rather than the routine — what is actually growing in there, what each smell tells you about where it lives, and when it stops being housekeeping and becomes a repair — see why a washing machine smells.

Frequently Asked Questions