Why Your Washing Machine Smells Bad and How to Clean It in Cranleigh

Published July 2026 | Washing Machine Smells Bad How to Clean It

What Causes a Washing Machine to Smell Bad

Washing machine odours come from a handful of well-understood sources. Knowing which one you're dealing with makes it much easier to sort the problem properly rather than masking it with fragrance tablets and hoping for the best.

Mould and mildew on the door seal. The rubber gasket around the door on front-loading machines is the number one culprit. Water and fluff collect in the folds, and if the door is kept shut between washes, the damp environment is perfect for mould growth. You'll typically notice a musty, earthy smell - similar to a damp cellar.

Detergent and fabric softener residue. Using too much detergent, or using non-HE (high-efficiency) detergent in modern machines, causes a soapy residue to build up inside the drum and in the dispenser drawer. This residue traps bacteria and starts to smell over time. Our engineers see this frequently with low-temperature eco washes, which have become very common in Cranleigh households over the last few years as energy costs have risen.

A blocked or dirty filter. Every washing machine has a drain pump filter, usually behind a small access panel at the bottom front of the machine. Lint, coins, hair grips, and general grime accumulate here. A blocked filter not only causes a smell - it can stop the machine draining properly and eventually damage the pump.

Standing water in the drum or hose. If your machine isn't draining fully between cycles, that standing water quickly turns stagnant. This is common in older Hotpoint and Beko models, though it can affect any brand. The smell is distinctly sulphurous or sewage-like rather than musty.

Bacteria in the drum. Modern eco washes at 30 or 40 degrees don't get hot enough to kill all the bacteria introduced by heavily soiled laundry. That bacteria builds up on the drum surface and drum paddles, particularly in Samsung and LG front-loaders with large-capacity drums that take a long time to dry out internally.

How to Diagnose Where the Smell is Coming From

Before you start cleaning, it's worth spending five minutes working out exactly where the smell originates. The fix is different depending on the source.

1. Open the door and smell the seal. Pull back the rubber gasket fold at the bottom of the door (around the 6 o'clock position). If there's black mould or slime there, the seal is the primary source. If you're based in Cranleigh and have a water softener fitted, you may find less limescale here than expected - but the mould can still develop regardless.
2. Check the dispenser drawer. Pull it out fully and lift out the fabric softener compartment insert. Smell it. If it smells like stale water or mildew, that's contributing to your problem. Look for pink or black slime inside the drawer cavity too.
3. Access the filter. Put a towel on the floor, open the filter access panel (usually bottom-right), and unscrew the filter slowly with a bowl ready for the water. Smell the water that drains out. A rotten-egg or sewage smell almost always points here.
4. Run an empty short cycle and smell the exhaust air. With the machine running, smell around the door seal and the exhaust vent at the back. This helps you work out whether the smell is coming from the drainage system or the drum itself.
5. Check the drum paddles. Look at the plastic paddles inside the drum. On Bosch and Siemens machines these can harbour significant bacteria under the rubber inserts on each paddle. Lift the insert with a coin - if there's black slime underneath, that's a major contributing source.

If you're not sure what you're dealing with after all that, the Voltrade GoFIX diagnostic tool can help you narrow it down before you call anyone out. It asks you a series of questions about your machine's symptoms and gives you a likely diagnosis along with recommended next steps.

DIY Cleaning vs Calling a Professional - When to Do Each

Most washing machine smells can be sorted without calling anyone. Here's how to go about it yourself, and how to know when you need an engineer.

DIY is appropriate when: the smell is musty or mouldy rather than sewage-like, the machine is draining normally, the smell started gradually, and you can see mould on the seal or residue in the drawer.

Here's a reliable DIY cleaning process that our engineers recommend to Cranleigh customers:

1. Clean the door seal thoroughly with a cloth dampened with a solution of one part white vinegar to one part water. Get right into the folds. Remove any visible mould and dry it off completely.
2. Remove the dispenser drawer, soak it in warm soapy water, and scrub it with an old toothbrush. Clean inside the drawer cavity with the same vinegar solution.
3. Remove and rinse the filter under the tap, clear out any debris, and refit it securely.
4. Put 250ml of white vinegar directly into the drum (not the drawer) and run the longest, hottest cycle your machine offers - 90 degrees where possible, or at least 60. Run it empty.
5. Once that cycle finishes, run another empty wash with two tablespoons of bicarbonate of soda in the drum to neutralise any remaining odour.
6. Leave the door open after every wash from this point on.

Call a professional when: the smell is sewage-like or sulphurous, the machine isn't draining properly, you've done the steps above and the smell returned within a few days, you can hear unusual noises alongside the smell, or the drum seal is visibly damaged or perished.

Residents across Cranleigh and the wider Surrey area can typically get an engineer out within 24 to 48 hours for this kind of job - it's generally a quick diagnosis and repair visit.

What a Qualified Appliance Engineer Will Do

When our engineers visit a home in Cranleigh to deal with a persistent washing machine smell, here's what the process typically involves.

First, we run a full diagnostic check - looking at the error code history on the machine (most modern machines from Bosch, Samsung, LG, and Hotpoint store fault codes even if they've never displayed an error to you), checking drainage performance, and physically inspecting the seal, filter, pump, and drum.

If the problem is a partially blocked drain pump or standpipe issue, we'll clear it and check that the pump impeller isn't damaged. A damaged impeller means water isn't being expelled efficiently, which leads to that distinctive stagnant smell after every wash.

For drum seal contamination on machines like Samsung AddWash or LG's TurboWash range, we carry out a professional-grade internal clean using specialist appliance cleaning agents that are considerably more effective than household vinegar solutions at breaking down biofilm.

If the door seal itself is perished, cracked, or has developed a tear that's permanently trapping water, we'll replace it. A new door seal on most common machines - Hotpoint, Beko, Bosch, or Indesit - typically takes under an hour to fit.

In some cases, particularly on older machines, we may recommend a descaling treatment to clear mineral deposits from the heating element. Surrey water can be moderately hard depending on where you are in the county, and limescale on the heating element does contribute to odours during hot washes.

Costs and What Affects the Price

Pricing for washing machine smell issues varies depending on what's actually causing the problem and what's needed to fix it.

Callout and diagnosis: A standard appliance engineer callout in Surrey typically costs between 60 and 90 pounds, which usually includes the first half-hour of labour. Some engineers will deduct the callout fee if you proceed with the repair on the same visit.

Professional cleaning service: If the engineer carries out a full internal clean - seal, filter, drum, dispenser, and drainage system - you're typically looking at 80 to 150 pounds depending on the machine and how long it takes.

Door seal replacement: Parts plus labour for a door seal replacement commonly comes to between 100 and 200 pounds. The seal itself varies in price by brand - genuine Bosch and Samsung seals tend to cost more than Hotpoint or Beko equivalents, though they're also more widely stocked.

Drain pump replacement: If the pump is the issue, a replacement fitted typically costs between 90 and 180 pounds for most common brands.

Parts availability can affect cost. For older or less common machines, parts sometimes need to be ordered, adding a day or two and occasionally a small premium. Our engineers working in Cranleigh and across Surrey carry common parts for the most popular brands on the van, which often means a same-visit repair without the delay of a return trip.

As a rough guide: if your machine is less than eight years old and in otherwise good condition, it's almost always worth repairing. If it's over ten years old and repair costs are heading above 200 pounds, it's worth having an honest conversation with the engineer about whether replacement makes more financial sense.

How to Prevent Washing Machine Smells in Future

Prevention is far easier than the cure here. These habits will keep your machine fresh with minimal effort.

Leave the door ajar after every wash. This is the single most effective thing you can do. It allows the drum and seal to dry out between cycles and stops mould from taking hold.

Run a hot maintenance wash monthly. Once a month, run a 60 or 90 degree empty cycle. You don't need any product - the heat alone kills most bacteria. If you want to add something, 250ml of white vinegar in the drum works well.

Use the right amount of detergent. Most people use too much. Check the dosing instructions on your detergent, and if you have softer water, reduce the dose further. Excess detergent leaves residue that feeds bacteria and contributes directly to that familiar mouldy smell.

Clean the filter every two to three months. Put a reminder in your phone. It takes less than five minutes and makes a real difference to both smell and drainage performance.

Wipe the door seal after every wash. A quick wipe around the inside of the seal with a dry cloth takes ten seconds and prevents mould from establishing. This is particularly worth doing in Cranleigh homes where the utility room or kitchen doesn't get much ventilation in the colder months.

Pull out the dispenser drawer occasionally. Give it a rinse under the tap every month or so. The fabric softener compartment insert is prone to slimy build-up if it's never removed, and that slime has a strong smell of its own.

Frequently Asked Questions

Why does my washing machine smell like rotten eggs?

A rotten egg or sulphur smell typically comes from bacteria in the drain system or a partially blocked filter allowing stagnant water to sit inside the machine. It can also be caused by a siphoning issue with the standpipe, where sewer gases are being drawn back through the drain hose. Check the filter first. If that's not the source, it's worth having an engineer look at the drainage set-up, particularly if the machine was self-installed or the drain hose was modified.

Can I use bleach to clean my washing machine drum?

You can use diluted bleach to clean the door seal and the drawer as a one-off treatment, but avoid putting neat bleach into the drum or running a full drum cycle with bleach. Bleach can degrade rubber seals and certain drum coatings over time. White vinegar or a proprietary washing machine cleaner such as Calgon or Dr. Beckmann Service-It are safer and effective for regular maintenance without the risk of long-term damage.

Why does my Bosch washing machine still smell after I've cleaned it?

On Bosch front-loaders, persistent smells after cleaning are commonly caused by bacteria trapped under the rubber inserts on the drum paddles - these are easy to miss during a standard clean. Lift the inserts with a coin and clean underneath them. On some older Bosch models, the drum bearing seal can also weep slightly, allowing water to pool behind the drum where it's inaccessible. If that's the case, you'll need an engineer to assess whether a repair or replacement is more appropriate.

How often should I clean my washing machine to prevent smells?

A monthly hot maintenance wash, a filter clean every two to three months, and a wipe of the door seal after each wash will keep most machines fresh year-round. If you regularly wash at 30 degrees to save energy - common in Cranleigh households since energy prices rose - increase the maintenance wash to every three weeks. Low-temperature programmes don't self-clean the drum the way a hot wash does, so the bacteria build-up happens faster.

Is a smelly washing machine the landlord's responsibility to fix?

In most tenancy agreements, washing machines are considered tenant-maintained appliances where they form part of the furnished inventory. However, if the smell is caused by a mechanical fault - a failed pump, a perished seal, or a drainage defect that pre-dated your tenancy - your landlord is typically responsible for the repair cost. If you're a Cranleigh tenant and unsure of your position, document the fault in writing before attempting any repairs yourself, and ask the landlord to arrange a qualified engineer visit.