Washing machine smells musty or of bad eggs (all brands)
✅ Safe to check yourself
This is a common, low-risk check most people can do safely. Always unplug the appliance (or isolate power) before touching internal parts.
A musty, damp-towel smell (or worse) from a washing machine is almost always biofilm — a build-up of detergent residue, fabric softener, and trapped moisture — growing inside the drum, door seal, and detergent drawer. It’s extremely common on modern low-temperature, low-water-use machines, which don’t get hot or full enough on everyday cycles to flush this out naturally.
What to check and do
- Pull out the detergent drawer fully (most slide out further than they first appear to, sometimes with a small release catch) and check behind it — this area collects a thick sludge that’s a major source of the smell.
- Clean the door seal thoroughly, folding back the rubber lip fully, as detailed in our door-seal-leak guide.
- Leave the door and detergent drawer open between washes to let the drum air out — this alone prevents most of the problem.
- Run an empty maintenance wash monthly at the highest temperature your machine allows (often a dedicated “drum clean” or “hygiene” cycle, or a 90°C cotton wash) with either a proper washing machine cleaner or a cup of white vinegar in the drum — this melts and flushes out built-up residue that everyday 30-40°C washes simply can’t reach.
- Check the drain pump filter isn’t holding stagnant trapped water, as covered in our drainage guides.
When to call an engineer
This is very rarely a fault — it’s almost always solved by cleaning. If the smell persists after a proper hot maintenance wash and thorough seal/drawer cleaning, it’s worth checking the drain hose route for a section that traps standing water, but a genuine mechanical cause is uncommon.