Why Your Washing Machine Smells Bad — And How to Fix It
A washing machine that smells bad is not just unpleasant — it actively makes your laundry smell worse. A musty, eggy, or sewage-like odor from the machine transfers directly to your clothes. This guid
By Olivia Perez
Tested and reviewed by hand9 min read
Why Your Washing Machine Smells Bad — And How to Fix It
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A washing machine that smells bad is not just unpleasant — it actively makes your laundry smell worse. A musty, eggy, or sewage-like odor from the machine transfers directly to your clothes. This guide explains the specific causes of washing machine odor, how to eliminate it completely, and how to prevent it from coming back.
Quick Answer: Why Your Washing Machine Smells
- Front-loaders: Most often the rubber door seal — mold grows in the trapped moisture inside the fold
- Top-loaders: Usually the drum interior or the area under the agitator
- Eggy/sulfur smell: Bacteria in standing water, often in the drain pump or hose
- Overall musty smell: Detergent residue buildup feeding mold throughout the machine
- Fix: Hot cycle with two cups of white vinegar, scrub the door seal, and run a cleaning cycle monthly
The Most Common Causes of Washing Machine Odor
Mold on the door seal (front-loaders)
The rubber gasket around the door of a front-loading washing machine is designed to create a watertight seal. The problem is that water and detergent residue collect in the folds of the gasket and stay there after the cycle ends. In the dark, enclosed environment behind the seal, mold establishes quickly — often within weeks of regular use if the machine is not properly maintained. Black or gray discoloration inside the door gasket fold is mold.
Detergent residue buildup
Using too much detergent — especially thick liquid detergent — leaves residue in the drum, dispenser, and hoses. This residue is food for mold and mildew. Ironically, the more detergent you add trying to clean clothes, the more you feed the problem. Powder detergent can leave clumps; liquid can leave a film. HE machines are especially vulnerable because they use less water, meaning less rinsing. See Signs You're Using Too Much Detergent and How Much Laundry Detergent to Use to recalibrate your dose.
Standing water in the drum or hose
Water that does not drain fully from the machine stays stagnant and breeds bacteria. A partial drain clog, a kinked drain hose, or a pump filter blocked with lint and debris can all cause standing water. If your machine smells like eggs or sewage, this is usually the cause — the smell is hydrogen sulfide produced by anaerobic bacteria in stagnant water.
Closed machine between uses
Closing the washing machine door immediately after use traps moisture in a dark, warm space — ideal for mold. Front-loaders especially need to be left open between uses to allow the drum and gasket to dry. Many people keep the door closed between uses without realizing it creates the conditions for mold every single wash.
Low-temperature washing habits
Cold water washing is excellent for the environment and for most fabrics, but bacteria and mold thrive in cool, damp fabric. Machines that are only ever used on cold cycles never get a hot wash to kill mold in the drum itself. An occasional hot cycle — or a dedicated machine cleaning cycle — counteracts this.
How to Clean a Smelly Washing Machine
Step 1: Clean the door seal (front-loaders)
Pull back the rubber gasket fold around the front door and inspect it carefully. Wipe away any visible mold or residue using a cloth dampened with undiluted white vinegar or a diluted bleach solution (one tablespoon bleach to one cup water for non-fabric surfaces). Work your way all the way around the seal, including the very back where it folds deepest. Rinse with a clean damp cloth afterward.
Step 2: Clean the detergent drawer
Remove the detergent dispenser drawer completely if it pulls out. Soak it in warm water with a splash of white vinegar, scrub with an old toothbrush, and rinse thoroughly. Wipe the drawer cavity in the machine with a damp cloth. Product residue and mold accumulate in the drawer channels and drip into the drum with every wash.
Step 3: Run a hot cleaning cycle with white vinegar
- Add two cups of distilled white vinegar directly into the drum (not the dispenser)
- Add half a cup of baking soda into the drum as well
- Run on the hottest cycle available — usually a "Sanitary," "Clean," or 90°C setting
- Do not add clothes or other detergent to this cycle
The hot water dissolves detergent residue, the vinegar kills mold and bacteria, and the baking soda deodorizes the drum interior. This combination covers the full spectrum of washing machine odor causes.
Step 4: Run a rinse cycle
After the cleaning cycle, run one additional empty rinse cycle with plain water to flush out any remaining vinegar or baking soda residue from the drum, hoses, and pump.
Step 5: Clean the pump filter (if accessible)
Most front-loading and some top-loading machines have an accessible pump filter, usually behind a small panel at the bottom front of the machine. This filter catches lint, coins, and debris before they reach the pump. A clogged filter is a common cause of odor and drainage issues. Refer to your machine's manual — the filter should be cleaned every one to three months. Place a towel and a shallow tray underneath before opening, as water will drain out.
Step 6: Leave the door open
After cleaning and after every subsequent wash, leave the door — and the detergent drawer — open for at least a few hours to allow moisture to evaporate. This single habit prevents the vast majority of mold growth in washing machines.
Front-Loader vs Top-Loader: Different Problems
Front-loaders
Front-loaders are more vulnerable to mold because the horizontal drum orientation means water always pools at the bottom of the door seal. The seal itself, the glass door interior, and the drum bottom are all chronically damp. Front-loaders require more active maintenance — door seal cleaning and post-use ventilation are non-negotiable. They do, however, typically offer a dedicated drum-clean cycle that helps.
Top-loaders
Top-loaders are better ventilated by design — the vertical drum opening allows more airflow and water drains more naturally away from sealing surfaces. However, they can still develop odor from detergent buildup under the agitator post or in the drum crevices. In top-loaders with no drum-clean function, running a hot cycle with a washing machine cleaner tablet or the vinegar method monthly keeps odor at bay.
Using Washing Machine Cleaning Products
Dedicated washing machine cleaning tablets (Affresh, Dr. Beckmann, and similar products) are formulated to dissolve detergent residue and kill mold without damaging machine components. They are a convenient alternative to the vinegar method and are particularly effective for monthly maintenance once you have done a deep clean with vinegar. They are not a substitute for physically cleaning the door seal — use them alongside, not instead of, the manual cleaning steps.
When the Smell is Sewage or Eggs
If your machine smells specifically like sewage or rotten eggs, the problem is likely bacterial — either in stagnant water or in the drain hose. Check that the drain hose is not submerged too deep into the standpipe (the connection to your household drain). A hose submerged too deeply can siphon wastewater back into the machine. The drain hose end should sit loosely in the standpipe, not sealed into it. If that checks out, run the cleaning cycle as described above and clean the pump filter.
Preventing Washing Machine Odor Long-Term
- Leave the door and drawer open after every wash
- Run one hot cycle per week — or use the drum clean setting
- Use the correct dose of detergent — excess detergent is the top cause of buildup
- Use HE detergent in HE machines — standard detergent creates far too much suds in HE machines, leaving residue everywhere; see HE Detergent Guide
- Clean the door seal monthly (front-loaders)
- Clean the filter every one to three months
- Never leave wet laundry in the machine
Frequently Asked Questions
Will running a hot cycle alone fix a smelly washing machine?
A hot cycle helps but is rarely enough on its own if mold is already established on the door seal. You need to physically clean the seal with vinegar or diluted bleach — a cycle with water cannot reach into the folds of the gasket effectively enough to scrub away embedded mold.
Is it safe to use bleach in a washing machine?
Yes — diluted bleach is effective for cleaning visible mold from the door seal when applied with a cloth. For a drum cleaning cycle, use either white vinegar or a dedicated washing machine cleaner. Bleach and vinegar should never be mixed — the combination produces chlorine gas, which is toxic. Use one or the other, never both in the same cleaning session.
How often should I clean my washing machine?
Once a month is the standard recommendation for the drum-clean cycle. Wipe the door seal every two to four weeks in front-loaders. Clean the filter every one to three months. Clean the detergent drawer whenever you see buildup.
Can I use essential oils to freshen my washing machine?
Adding a few drops of tea tree oil or eucalyptus oil during a cleaning cycle provides a pleasant scent and some antimicrobial effect, but it does not replace vinegar or detergent residue removal. Use it as a follow-up addition, not a primary cleaning agent.
My machine was cleaned but clothes still smell musty — why?
If cleaning the machine has not resolved the smell on clothes, the problem may be in how the clothes are being dried. Clothes not dried promptly or thoroughly develop their own mildew. See How to Remove Mildew Smell from Clothes for treating affected garments directly.
The Bottom Line
A smelly washing machine almost always comes down to mold on the door seal, detergent residue buildup, or stagnant water — and all three are fixable. Clean the seal manually, run a hot vinegar cycle, clean the filter, and then make leaving the door open after every use a permanent habit. Monthly maintenance takes less than ten minutes and keeps odor from returning.
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