Bad odour from washing machine: Causes, fixes, and prevention

A musty, sour smell from your laundry room is a clear signal that something's not right with your washing machine. The most common culprit behind a bad odour from your washing machine is a grimy buildup of mould, mildew, and bacteria. This gunk loves the warm, damp corners of your machine, creating a slimy layer known as biofilm.

Pinpointing Why Your Washing Machine Smells

That lingering pong usually traces back to a few key issues. Much like other household appliances, your washing machine can quickly become a breeding ground for harmful yeast and mold, which is what you're smelling.

Let's break down the main sources:

• Biofilm Buildup: This is the slimy film you might feel inside the drum or on the door seal. It's a mix of old detergent, fabric softener residue, and body soils that have stuck around and started to fester.
• Low-Temperature Washes: While great for saving energy, cool wash cycles often aren't hot enough to kill off the bacteria and mould spores that cause these smells.
• Trapped Debris: Stagnant, smelly water can get stuck in hidden filters and drain pipes. A stubborn problem might mean you need to learn how to unblock a washing machine waste pipe to properly clear it out.

Domestic odours from biofilm are a common issue many households face, but thankfully, it's one you can fix.

Getting Stuck in for a Proper Deep Clean

Now that you know what’s causing the smell, it’s time to give your machine a targeted deep clean. Just running a hot cycle won't cut it; we need to get into the problem areas where gunk loves to hide.

First, tackle the rubber door seal—a prime suspect for trapping grime. Gently pull back the folds of the seal and use a damp cloth to scrub away any hidden residue.

Next, slide out the detergent drawer. You’ll probably find some slimy build-up inside. Give it a good scrub in the sink with warm, soapy water until it's clean.

Don't forget the filter, usually tucked away behind a flap at the bottom of the machine. It catches lint, tissues, and fluff, so cleaning it is a must-do step. Check your manual if you're unsure how to open it.

To finish, run a two-part cleaning cycle. First, put two cups of white vinegar directly into the drum and run the machine on its hottest setting. When it’s finished, add half a cup of bicarbonate of soda and run another hot cycle. This combination will sanitise the drum and flush out the pipes. For more detailed advice, check out our complete guide on how to clean your washing machine.

Creating Habits To Keep Odours From Returning

A deep clean is a great reset, but the secret to lasting freshness is forming simple habits. These small actions stop mould and mildew from growing and prevent that bad odour from returning.

The easiest thing you can do is leave the door and the detergent drawer slightly ajar after each wash. This allows air to circulate, letting the drum and seals dry out completely.

It’s also worth thinking about how you load the machine. Research from Electrolux found that a staggering 71% of UK adults often run small, partial loads. This can make smells worse by trapping moisture and contributes to the musty smells that cause half of us to rewash perfectly clean clothes.

For a deeper dive, our comprehensive appliance maintenance guide is packed with more useful tips. And remember, maintaining other laundry appliances like your tumble dryer plays a part too.

When to Call a Professional Appliance Engineer

Sometimes, no matter how much you scrub, that funky smell won't quit. If you've given your machine a thorough deep clean and the odour returns immediately, the problem likely runs deeper than surface grime.

Watch for red flags like persistent smells, strange grinding noises, or water not draining properly. These symptoms often point to a serious issue, like a clog in the main drain pump or an internal hose that you can't reach.

A bad odour from your washing machine is more than just an annoyance; it's one of the most common domestic odour complaints in the UK. Data shows that issues at home account for over half of all odour reports nationwide. You can read more in the UK's odour complaints report on Direct365.co.uk.

If you’re dealing with a stubborn smell, it’s time to call the experts. Our engineers can get to the root of the problem, ensuring your machine is running smoothly and smelling fresh again.

Your Washing Machine Smell Questions Answered

Ever pulled a load of laundry out, only for it to smell worse? You’re not alone. Here are quick answers to common questions about smelly washing machines.

Why Do My Clothes Smell Worse After Washing?

This is a classic sign your machine is harbouring mould and bacteria. During a cycle, these microbes transfer from the seal and filter onto your fabrics. That damp or musty smell is your machine's cry for help—it needs a deep clean.

Is It Bad to Leave Wet Laundry in the Machine?

Yes! A drum full of damp laundry is the perfect breeding ground for mould and mildew, which causes that unmistakable musty smell on your clothes and in the machine. Make it a rule to unload laundry as soon as the cycle finishes.

How Often Should I Deep Clean My Washing Machine?

For an average household, a thorough deep clean every one to three months is a good rule to keep bad smells at bay. However, if your machine is constantly running or you live in a hard water area, aim for a clean once a month.

Still Smelly? Troubleshooting Common Problems

So, you’ve followed all the steps but you’re still getting a whiff of something unpleasant. A lingering bad odour from your washing machine doesn’t automatically mean you’ve done anything wrong. It often points to a problem you can't easily see, like a blockage somewhere in the system.

Why Is the Smell Still There?

A stubborn smell after cleaning almost always means the source is tucked away in a less accessible part of the machine, like a partially blocked drain hose or a filter that’s trapping foul, stagnant water.

Pause before reaching for harsh bleach. While it might seem like a quick fix, bleach can eat away at rubber seals and damage internal components over time. A more targeted approach is always safer and more effective.

Troubleshooting Your Deep Clean

This table helps you figure out what's gone wrong and how to fix it.

If you've tried everything and that funky smell won't budge, the problem is likely a clog deep within the appliance that needs a specialist’s touch.

At Go Assist, our certified engineers can get to the root of the problem and fix it fast, often with same or next-day appointments. Book your washing machine repair online today and finally say goodbye to that bad odour for good.