Leave the washer door open so the drum dries

Your clothes come out smelling stale. Or the rubber seal around the door has gone black and slimy, and you are wondering whether the machine is finished, or whether you need to buy something to clean it.

Many people who have been through this point at damp rather than dirt: a closed, wet drum is where mould grows. Leave the washer door open after the last load, and the detergent drawer too, so the inside can dry. It costs nothing and it works on the cause people name. It is not the only thing that matters, as the sections below show, and it has two exceptions you need before you start: a cat or small child who can reach the machine, and a machine in a shared laundry room.

Why the door and the drawer

Many people say leaving the door or lid open after a wash lets the moisture escape, so mould has less to grow in. Some people say their manuals recommend it; check yours. Many people say the detergent drawer should be left open as well, because residue builds up there.

If you have a front-loader, some people say water sits in the folds of the rubber seal, and wiping the seal dry after use clears the water, hair and lint that help mould grow.

Wet clothes matter too. Some people warn that laundry left sitting in the drum goes sour: one person puts the limit at a couple of hours, and another says never overnight, even in a standard washer.

For scale, the US Environmental Protection Agency says that if damp materials are dried within 24 to 48 hours after a leak or spill, in most cases mould will not grow. Its figure is about water damage in buildings, not washing machines, so read it as a sense of how fast damp matters, not as a rule for your drum.

Use less detergent

Many people say using less detergent than the bottle recommends prevents the soap scum that feeds mould. One person explains why: high-efficiency machines use little water, so extra soap does not rinse out, and it leaves a film. Another says overloading the drum stops it rinsing properly, and that fabric softener adds more residue.

One person who says they repair appliances keeps their own door closed all the time with no smell, and blames too much detergent, overloaded drums and clothes left sitting instead of the door. One person says switching from liquid to powdered detergent stopped a musty smell even with the door left open, though that goes against some makers’ advice, so check your manual first. One person points out that dish soap can foam too much in these machines.

When the door cannot stay open

This is where people split, and the reasons are about your home, not about right and wrong.

• Pets. Some people warn that an open door is a hazard for a cat, which can climb in and be hurt when the machine is started. The page’s own cost-free precautions are to look inside the drum before every start, and, if a cat or small child can reach the machine, to keep the door shut and wipe the seal dry instead.
• Pests. Some people raise the worry that an open lid lets spiders in. One person finds that too unpleasant and shuts the lid despite the mould risk.
• Space. Some people note an open door can block a narrow laundry room. One person describes a homemade stopper that holds the door slightly ajar; how to build it is not covered here.
• Seals. One person warns that leaving the door open on a front-loader can ruin the rubber seals. Some people leave a front-loader only slightly open instead of wide.
• Top-loaders. One person says a top-loader does not seal and dries out fine closed. Another says even top-loaders keep some moisture after draining, and a third says their closed top-loader still turns musty if it sits shut for more than a day or two.

If you cannot leave it open, one person says the machine’s own built-in cleaning cycle is an alternative, and another runs an empty hot cycle with a cleaning product once a month. Wiping the seal dry after each use costs nothing, and some people say it clears the water, hair and lint that help mould grow.

If it already smells

Many people suggest an empty hot cycle with white vinegar, and some people prefer a bleach cycle, or a cleaning product made for washing machines. One person says the hottest setting works best, and another says vinegar did nothing for their existing smell. People argue about which cleaner works better, and this page cannot settle that.

Use one cleaner or the other, never both. Some people give this warning with force, and the US CDC says the same: household bleach can release chlorine gas when it is mixed with certain other cleaning products. The safe choice costs nothing: pick one, and do not pour the other into the machine at all. Some people also point out that baking soda and vinegar cancel each other out when they meet, so use one at a time.

Mould that has already set into the rubber is harder. One person warns it can eat into the seal and be very difficult to remove, and another that bleaching a seal with mould etched into it can make the rubber crack. Some people suggest replacing just the seal rather than the whole machine. This page does not cover how to do that, or whether vinegar or bleach hurts a seal over years.

The CDC says people with asthma or allergies may have severe reactions to mould, and that people with a weakened immune system or a long-term lung condition may get lung infections from it. If that is you, consider handing the scrubbing of a mouldy seal to someone else.

The filter at the bottom

Some people say there is a small panel low on the front of the machine that covers a trap catching coins, socks and hair, and that a clogged trap adds to the smell and the clogs. One person says to clean it every couple of months. Some people call it messy and unpleasant. One person warns that if someone starts a load while the trap is out, the floor floods, so keep the door shut or marked while you work. The panel opens differently on different machines, and water will come out when it does, so read your manual before you open it.

Who this page is not for

If you share a laundry room or a laundromat machine, the door is not yours to leave open. What you can do is look at your own wash: use less detergent and take your wet clothes out promptly. Nothing here covers how to get a shared machine cleaned.

If you have a cat or a small child who can reach the machine, the door-open advice is the part to skip, and the seal wipe and the drum check are the parts to keep.

If you are choosing a new machine, people argue about front-loaders against top-loaders, and this page does not try to decide which to buy. For mould on walls, tile and caulk rather than inside a machine, see the mould page linked below; for the lint in a dryer, the dryer page.