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Quick answer: a smelly washing machine is almost always down to a build-up of detergent residue, mould and bacteria in the places water doesn’t fully drain away — the rubber door seal, the detergent drawer, the filter, and the waste drain hose. You can usually fix it in an afternoon by cleaning those four spots and running a hot maintenance wash, then keep it from coming back by leaving the door and drawer ajar between washes and running that hot wash monthly. I’ve walked through the full process in my washing machine smell video, and I’ve broken every step down below too.
Why does a washing machine start to smell?
It’s almost never the machine itself — it’s what’s living inside it. Modern washing machines, especially efficient ones, use less water and lower temperatures than older models, which is great for your energy bill but means there’s less heat and less rinsing to kill off bacteria and flush away residue. Over time that leaves damp, dark, detergent-fed conditions in exactly the places you can’t easily see: behind the rubber door seal, inside the detergent drawer, in the filter housing, and along the corrugated waste drain hose. Mould and bacteria thrive there, and that’s what you’re actually smelling.
Washing mostly on cool, quick cycles makes this worse over time, since a 30°C wash doesn’t get hot enough to break down the biofilm building up inside the drum and pipework. None of this means you’re doing anything wrong day to day — it just means the machine needs the occasional deeper clean that a normal wash cycle doesn’t do for you.
How to fix a smelly washing machine, step by step
1. Clean the detergent drawer
Start here — it’s the easiest win. Most drawers pull all the way out (there’s usually a small catch or release tab underneath). Soak it in warm soapy water to loosen the caked-on detergent and fabric softener residue, then use an old toothbrush to get into the corners and channels, which is where the gunk actually collects. While it’s out, wipe out the cavity it sits in too, since that gets just as grimy and is easy to forget. Make a habit of leaving the drawer open a crack between washes so it can dry out fully — a monthly clean is enough to stop it building back up.
2. Run a hot maintenance wash
Once a month, run an empty cycle at 90°C (or your machine’s hottest setting). This is the single biggest fix for smell caused by everyday cool washing, because it’s hot enough to break down the bacteria and biofilm that lower-temperature cycles leave behind. You can run it completely empty, or add a dedicated washing machine cleaner (see below) for a deeper clean.
3. Clean the rubber door seal (gasket)
Pull the rubber seal back and look inside the fold — this is usually where the smell is strongest, since soap scum and moisture sit trapped in there after every wash. Wipe it out thoroughly with warm soapy water and an old cloth or toothbrush, working right into the fold rather than just across the visible surface. One thing to avoid: don’t use vinegar on the rubber seal. It’s a popular “natural” tip, but vinegar’s acidity can degrade rubber over time and leave it perishing and cracked, so stick to warm soapy water or a proper washing machine cleaner instead.
4. Leave the door and drawer open between washes
This is the cheapest prevention step there is, and it costs nothing: after each wash, leave the door ajar (not sealed shut) so the drum can air out and dry properly instead of sitting damp and sealed in the dark, which is exactly what mould needs to take hold. Do the same with the detergent drawer.
5. Clean the filter and drain pump
Most front-loaders have a small hatch near the bottom, front corner, which hides the filter and drain pump. Before you open it, put a towel down and a shallow tray in front of it, since there will be some water still in the pipe. Unscrew the filter cap slowly and let the water drain into the tray, then pull the filter out fully — this is where coins, hair, buttons and general debris collect, and it’s a common source of smell that people don’t think to check. Give the filter itself a good rinse and clean out the housing it sits in before screwing it back in.
6. Use a dedicated washing machine cleaner
A proper washing machine cleaner reaches further into the drum and pipework than a wipe-down can, and it’s worth adding one to your monthly hot maintenance wash. If you’re in a hard water area, a descaler is worth alternating in too, since limescale build-up on the heating element makes washes less effective over time and can contribute to that lingering damp smell. Two I use myself and have linked below:
- Deep Clean Washing Machine Cleaner — for the monthly hot maintenance wash.
- Dettol Washing Machine Cleaner, Lemon Breeze — a good everyday option that also leaves a fresh scent rather than just neutralising the smell.
7. Check the waste drain hose
If you’ve done all of the above and there’s still a whiff, the culprit is often further along: the corrugated waste drain hose at the back of the machine can trap pooled water and grime in its ridges, out of sight. A flexible drain snake is the easiest way to clear this without pulling the whole machine out from the wall:
- Flexible drain snake — feeds into the waste hose to clear trapped debris.
How to stop it coming back
Once it’s fixed, keeping it that way is mostly about habits rather than more cleaning products:
- Leave the door and detergent drawer ajar between washes so the machine can dry out.
- Run an empty 90°C maintenance wash once a month, ideally with a washing machine cleaner.
- Don’t overload the detergent drawer — too much detergent or fabric softener doesn’t rinse away fully and is one of the main things feeding the residue build-up.
- Wipe out the door seal every week or two as part of your normal cleaning routine, rather than waiting until there’s a smell to deal with.
Quick answers
Why does my washing machine still smell after I’ve cleaned it?
Usually because only one of the four trouble spots was cleaned. The door seal, detergent drawer, filter and drain hose all need checking — cleaning just the drum or just the seal often leaves the actual source untouched. Give the maintenance wash and filter a look if you’ve only done the seal so far.
How often should I clean my washing machine?
A quick wipe of the door seal and drawer every week or two, plus one empty 90°C maintenance wash a month. That’s enough to stop residue building up to the point it starts to smell.
Can I use vinegar to clean a washing machine?
Not on the rubber door seal — vinegar’s acidity can degrade rubber over time and leave it perishing. It’s better suited to descaling hard, non-rubber parts occasionally rather than as a routine cleaner. For regular cleaning, warm soapy water or a proper washing machine cleaner is the safer choice. As I’ve covered when I tested what baking soda can actually clean, mixing vinegar with baking soda also isn’t the powerful combination people assume — the two react and largely cancel each other out.
Is it safe to use bleach in a washing machine?
Check your machine’s manual first, as some manufacturers advise against it because it can degrade rubber and plastic components with repeated use. A dedicated washing machine cleaner is formulated specifically to be safe on those parts while still being strong enough to break down mould and residue, so it’s the lower-risk option for regular maintenance washes.
Why does washing on cool cycles make the smell worse?
Cool washes (around 30°C) are efficient for everyday laundry, but they don’t get hot enough to break down the biofilm and bacteria that build up inside the drum and pipework. That’s exactly what the monthly 90°C maintenance wash is for — it does the job your regular washes aren’t hot enough to do.
If you’d rather watch the whole process than read it, I’ve covered all of this step by step in my smelly washing machine video. And if limescale in a hard water area is part of what you’re dealing with, it’s worth reading how to remove soap scum from shower glass too — the same hard water build-up shows up in both places.
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