How often should you run your washing machine clean cycle?

Mould and detergent buildup cause odors and dirty laundry.

The smell is the obvious symptom, and it can transfer to clothes. CHOICE adds that the waxy build-up from laundry products, together with mould, can damage the drum and the door seal, and a drain pump filter left to clog can stop the machine draining properly.

1. Run a hot maintenance wash. Empty machine, on the drum clean or tub clean programme if there is one, otherwise the hottest cycle. Which? suggests 60 to 90 degrees Celsius where there is no service programme, and some makers specify 90 or 95, so check the manual.
2. Use the cleaner your manual recommends. Usually a proprietary washing machine cleaner, used without detergent. Which? advises against vinegar, which it says could erode the drum bearings and other internal parts, and against putting bicarbonate of soda straight into the drum.
3. Clean the door seal thoroughly. On a front loader, pull back the folds of the rubber gasket and wipe inside with a cloth and warm soapy water. Water, hair and lint collect at the bottom of it.
4. Remove and wash the detergent drawer. It lifts out on most machines. Scrub the compartments and brush out the recess it slides into.
5. Clean the drain pump filter. On a front loader it sits behind a small hatch at the bottom front. Unplug the machine, let the water cool if a hot cycle has just run, and put a shallow tray and towels down first, because water will come out. Coins, buttons and hair collect here.
6. Wipe the drum and leave the door ajar. Leaving the door and the drawer open between washes lets the machine dry out, which is what Samsung, LG and CHOICE all advise.

• A musty or sour smell from the drum, or on clothes after washing
• Black specks or slime visible in the door seal or on clothes
• Detergent drawer residue that returns quickly after cleaning
• The machine failing to drain fully, which points to the pump filter

• Only ever washing at low temperatures and never running a hot maintenance wash
• Using too much detergent. CHOICE says a third or even a quarter of a scoop is often enough for a good wash, and that overdosing can damage the drum and seals
• Heavy use of fabric softener, which CHOICE calls a big contributor to build-up
• Closing the door immediately after a wash, trapping moisture inside
• Never opening the pump filter, until the machine stops draining
• Mixing bleach and vinegar when cleaning the seal. LG allows either one, diluted, but never both together

• Households washing mostly at low temperatures need this more often
• Heavy fabric softener use adds to the build-up
• Front loaders have the door seal and pump filter to look after as well as the drum
• A musty smell that is already there needs more than one cycle. LG suggests a tub clean once a week for three weeks

A machine that will not drain after the pump filter is cleared, leaks from the base, or makes a loud rumbling noise on spin needs a technician. Get a quote before agreeing to a major repair on an older machine.