The quick answer
A washing machine that smells of mould, eggs or sewage is almost never a fault with the machine itself. The smell comes from a hidden build-up of bacteria, mould and detergent residue — together called biofilm — that thrives in the warm, damp parts of the drum, seal and pipes. Clear the biofilm and keep the inside dry, and the smell disappears.
Common causes of a smelly washing machine
- Biofilm in the drum and pipes: low-temperature washes and liquid detergent leave a sticky film that bacteria feed on.
- A dirty rubber door seal: on front-loaders, water and gunk collect in the folds of the gasket, turning black and musty.
- Standing water in the filter or sump: stale water that never drains away smells stagnant.
- A blocked or badly fitted drain hose: a sewage smell usually means drain gases are coming back up the hose.
- Leaving wet washing inside: damp clothes left for hours breed odour fast.
- Too much detergent or softener: excess residue feeds mould rather than rinsing away.
Step-by-step fix
- Wipe the door seal. Pull back the rubber gasket and clean every fold with a cloth dipped in a 50/50 white vinegar and water mix. Remove any trapped coins, hair and slime.
- Clean the detergent drawer. Remove it fully, scrub off mould with an old toothbrush, and clear the recess it sits in.
- Empty the drain filter. Place a shallow tray underneath, unscrew the filter at the bottom front, and rinse out the trapped lint, water and debris.
- Run a hot maintenance wash. With the drum empty, run the hottest cycle (90°C if available) with 250 ml white vinegar or a dedicated washing machine cleaner.
- Wipe and dry. After the cycle, wipe the drum dry and leave the door open.
How to prevent the smell coming back
- Leave the door and the detergent drawer slightly open between washes so the inside can dry.
- Run a hot maintenance wash once a month.
- Use the correct dose of detergent — more is not better.
- Remove washing as soon as the cycle ends.
- Run an occasional 60°C cotton wash instead of always washing cold.
For the full deep-clean routine, see our guide on how to clean the washing machine drum and filter, and our dedicated guide to running a maintenance wash.
When to call a technician
If a strong sewage smell persists after cleaning, the problem is likely the plumbing — a missing U-bend trap on the waste pipe or a badly installed drain hose lets sewer gas back into the machine. A plumber or appliance technician can refit the drain correctly.
Recommended products
A monthly cleaner keeps biofilm from returning between deep cleans.
Browse Washing Machine Cleaners on Amazon India ↗
Also worth reading: how to clean the rubber door seal — the most common source of a musty smell.