How to clean the drum, door seal, detergent drawer and drain filter, the usual sources of musty laundry and black flecks, for front- and top-loaders alike.
Start where water pools and where things stay shut while wet
Front-loader
Inside the rubber door seal, and the drain filter at the bottom front
Top-loader
The lint filter, and the hidden outer side of the drum
Drum clean
Oxygen-based cleaner and warm water, on the cycle your manual names
Never
Mix chlorine bleach with acidic cleaners
Where the smell comes from
The inside of a washing machine is always damp, and leftover detergent, body oils and lint feed bacteria and mold. In a front-loader, grime collects mostly in the folds of the rubber door seal and in the drain filter; in a top-loader, it builds up on the outer side of the drum, where you can't see it. Running a drum-clean cycle alone won't sort out the seal or the filter, so clean each part separately. These signs tell you it's time.
Laundry smells musty
Black flecks stick to clothes
A stale smell when you open the door
Slow draining or a drain error
Safety and preparation
Unplug the machine first, and turn off the water tap if you plan to touch the inlet filter. Right after a hot wash, water left inside can still be hot, so let it cool properly. Rubber gloves, an old toothbrush, a dry towel and a shallow tray are all you need. Designs vary between models, so check the manual or the maker's guidance for how parts come out. Forcing a part you don't know how to remove is a common way to snap a clip.
Unplug and turn off the water tap
Let it cool after a hot wash
Check the manual for how parts come out
Door seal and detergent drawer
Pull back the folds of a front-loader's rubber seal and you'll often find hair, coins and black grime. Remove the debris, wipe with water and a little washing-up liquid, scrub the grooves with a toothbrush and dry with a towel. If black mold is ingrained, lay tissue soaked in mold remover over it for a short while, but don't leave it long enough to damage the rubber; wipe it off thoroughly and ventilate. Pull out the detergent drawer, soak it in warm water to dissolve hardened residue, and check the ceiling of the slot it sits in.
Open the seal folds and remove debris first
Soapy water, then toothbrush, then dry towel
Remove and soak the detergent drawer
Check the ceiling of the drawer slot
Drain filter and lint filter
On most front-loaders the drain filter sits behind a small cover at the bottom front. Water will pour out when you open it, so lay a towel down and set a shallow tray underneath. If there is a thin drain hose beside it, empty the water through that first, then unscrew the filter slowly and clear out hair, lint and coins. After rinsing, screw it back in all the way; a loose filter leaks on the next wash. On a top-loader, remove the lint filter from the inside wall of the drum, empty it and rinse.
Put down a towel and tray first
Drain the water through the small hose
Clear debris and screw back in fully
On a top-loader, empty the lint filter
Running a drum-clean cycle
Use an oxygen-based cleaner and warm water in the empty machine. Choose the drum-clean cycle if there is one; otherwise pick the longest cycle at the highest temperature your manual allows. In a top-loader, filling it with water, dissolving the cleaner and leaving it to soak for a few hours before running it lifts loosened grime to the surface; scoop that out and run an extra rinse so it doesn't end up on your clothes. Ordinary high-foaming detergent in a front-loader can overflow with suds. Follow the manual for how often, and bring it forward if a smell returns.
Oxygen-based cleaner and warm water in an empty drum
Soak a top-loader, then scoop out floating grime
Finish with an extra rinse
Inlet filter and exterior
Where the water hose connects to the machine there is a small mesh screen that catches debris from the supply. When it clogs, water flows in slowly and cycles take longer. Turn off the tap, unscrew the hose and brush the screen gently with a toothbrush. Wipe the outside and the inner side of the door glass with a dry cloth, and never spray water directly onto the control panel. If the machine shakes hard during the spin, check that it is level and adjust the feet.
Turn off the tap before unscrewing the hose
Brush the mesh gently
Never spray water on the control panel
What not to mix, and common mistakes
The most dangerous mistake is mixing cleaners. Chlorine bleach combined with acids such as vinegar or citric acid releases toxic gas. Use one product at a time, and run a rinse cycle before switching to another. More cleaner doesn't mean cleaner results either; it can overflow with foam or trip a sensor error, so stick to the stated dose. Adding baking soda and vinegar together just makes fizz, as they neutralise each other and both lose their effect.
Never mix chlorine bleach with acids
Use the stated dose only
Run a rinse before switching products
Habits that keep it clean
Habits are what keep a clean machine clean. Take laundry out as soon as the cycle ends, and leave the door and detergent drawer open so the inside can dry. Wiping the water that collects in the bottom of a front-loader's seal with a dry towel cuts mold dramatically. In homes with small children, though, open the door only slightly or use the child lock, so no one can climb inside. If the smell persists after cleaning, or strange noises, leaks or drain errors keep coming back, don't take it apart yourself; have it checked by a service technician.