Washing Machine Smells Musty? How to Fix and Prevent It
Why a washing machine develops a musty or sour smell, how to clean the drum, seal, drawer and filter, and habits that keep laundry smelling fresh.
If clean laundry comes out smelling stale, the machine is usually the cause. Modern washing at low temperatures with liquid detergents is gentle on clothes but leaves residue behind, and warm damp places encourage bacteria and mould. The good news is that a thorough clean often solves it without any repair.
Why it happens
Several things combine:
- Low temperature cycles that do not heat the drum enough to break down residue.
- Too much detergent or fabric conditioner, which leaves a sticky film.
- A door shut tight between washes, trapping moisture.
- Residue in the seal, drawer and filter that feeds bacteria and mould.
- Standing water in hoses or the pump area after a poor drain.
A full clean, step by step
1. Wipe the door seal
The rubber door seal is the worst offender. Peel back the folds and look for black spots, hair and debris. Wipe with a cloth and a mild cleaning solution, such as diluted white vinegar or an appropriate mould cleaner, then dry thoroughly. Do not mix cleaning products.
2. Clean the detergent drawer
Slide the drawer out, pressing the release catch. Soak it in warm soapy water and scrub with an old toothbrush. Check the recess behind it too, where mould and sludge often hide.
3. Clean the drain filter
Follow the steps in our guide on washing machines not draining. Put a tray under the flap, drain the water and remove debris. A filter full of sludge produces a strong smell.
4. Run a hot maintenance wash
With the drum empty, run a hot cycle, typically 60 degrees or higher, using a washing machine cleaner or the quantity of detergent recommended by the manufacturer. Some people use a descaler. Check your manual before using vinegar or other substances, as some manufacturers advise against it.
5. Dry out
Leave the door and drawer open after the clean so that air can circulate.
Habits that keep it fresh
| Habit | Benefit |
|---|---|
| Leave door ajar after washing | Lets moisture escape |
| Use the correct detergent dose | Less residue |
| Run a hot wash monthly | Breaks down build-up |
| Remove wet clothes quickly | Stops musty laundry smell |
| Wipe seal after use | Stops mould forming |
| Clean filter regularly | Prevents blockages and odours |
Detergent and conditioner
More is not better. Overdosing leaves residue. Follow the label, adjusting for water hardness and load size. If you live in a hard water area, scale can also build up, see our note under related guidance in appliance running costs, where heating efficiency is discussed.
When the smell is not mould
- Burning smell. Stop the machine, unplug it and call an engineer.
- Rotten egg or drain smell. The waste pipe or trap may be dirty, or the machine's waste connection lacks an air gap.
- Chemical or hot-rubber smell. May be a new machine's initial run or a belt issue. Run an empty wash, and if it persists, seek advice.
If you cannot solve the problem, describe it clearly and ask for advice from a technician. See our guide on describing a fault. You can request offers on Compito if you want a professional to look at it.
A worked example
A household notices that towels smell damp even straight out of the machine. They wipe the seal and find a grey film, then pull out the detergent drawer and discover black residue in the recess. After scrubbing both and cleaning the filter, they run a 60 degree empty wash with a machine cleaner. The smell is gone the next day. They then switch to a smaller dose of detergent, wash at 40 degrees most weeks and run a hot cycle monthly. Prevention worked better than reacting to each smell.
Which clean to choose
| Option | Good for | Be careful of |
|---|---|---|
| Hot empty wash with cleaner | Regular maintenance | Follow the manual's temperature limits |
| Manual wipe of seal and drawer | Visible mould | Gloves and good ventilation |
| Descaler | Hard water areas | Not every manufacturer approves of all products |
| Filter clean | Smell plus drainage issues | Tray and towels needed |
Common mistakes
- Closing the door and drawer straight after every wash.
- Using only quick, cold cycles for months.
- Mixing bleach with vinegar or other cleaners, which can release harmful fumes.
- Ignoring the rubber seal because the drum looks clean.
- Washing smelly items repeatedly without cleaning the machine.
Edge cases
- Small flats with poor ventilation: the machine may stay damp, so keep the door open and ventilate the room.
- Rented homes: ask the landlord about replacing a heavily mouldy seal, which may be their responsibility.
- Washer-dryers: the same steps apply, and the dryer filter and condenser area also need cleaning.
- Hard water areas: scale can hold odours, so a periodic descale cycle may help.
When to call a professional
A smell of burning plastic, hot rubber or an electrical odour means stop and unplug. If the smell is a drain odour and the machine is connected to a standpipe or trap, a plumber can check the waste arrangement.
Frequently asked questions
Can I use bleach in my washing machine?
Some manufacturers advise against it, because it can damage seals and some parts. Check your manual and never mix it with other cleaners.
How often should I clean the machine?
A monthly hot cycle and a wipe of the seal after use is a sensible routine for most households.
Do front loaders smell more than top loaders?
They tend to hold moisture around the door seal, so they benefit from more attention to the seal and from leaving the door open.
Will a new machine solve the smell?
Only if the cause was the machine. If you keep using low temperatures and overdosing detergent, a new one will develop the same problem.
Does a mouldy seal need replacing?
Light mould usually cleans off. If staining is deep, the rubber is torn or the smell returns quickly, replacing the seal may be worthwhile, and an engineer can advise.