If your washing machine smells like rotten eggs, the problem is almost always hydrogen sulfide gas building up inside the drum, drain, or seal. That sulfur smell comes from bacteria feeding on leftover detergent, fabric softener, skin cells, and lint in a damp, warm machine. It’s common in front-load washers, top-load washers, and high-efficiency models alike, and it won’t go away on its own. This article walks you through exactly what causes the odor, how to find the source, how to clean it, and how to keep it from coming back.
Key Takeaways
- Run an empty hot cycle with two cups of white vinegar or a washer-cleaning tablet to kill odor-causing bacteria.
- Wipe the rubber door gasket and detergent drawer after every few loads to remove trapped moisture and residue.
- Leave the washer door open between loads so the drum can dry completely.
- Check the drain hose and standpipe for clogs if the smell smells like sewage rather than mildew.
- Call a plumber if you smell gas near the washer or if the odor persists after two full cleanings.
Safety: Inside a mains-powered machine, the parts behind the outer cover can hold a dangerous electrical charge even after it has been unplugged — that’s why they sit behind a cover. Opening the housing, or testing or replacing anything behind it, is a job for a qualified technician, never a home repair.
Common Causes When Your Washing Machine Smells Like Rotten Eggs
Most rotten-egg odors come from one of four places inside or around the machine. Identifying the source tells you which fix to use first.
Bacterial Buildup in the Drum
Low-temperature washes and liquid detergent leave a biofilm on the inner drum. Bacteria grow in that film and release hydrogen sulfide, which smells like rotten eggs. Front-load machines are especially prone because the horizontal drum holds moisture against the door seal.
Dirty Rubber Door Gasket
The gasket on a front-load washer traps water, hair, and detergent after every cycle. If you don’t wipe it, mold and bacteria colonize the folds and create a strong sulfur smell every time you open the door.
Clogged Drain Pump Filter
Lint, coins, and small pieces of clothing collect in the drain pump filter. Standing water around that debris becomes stagnant and smells like rotten eggs, especially if the machine sits idle for a day or two.
Sewer Gas Through the Drain Hose
If the standpipe or drain hose lacks a proper P-trap, or if the trap has dried out, sewer gas can rise back into the washer. That odor is often mistaken for a machine problem when it’s actually a plumbing issue.
Where the Smell Usually Comes From
Use this table to match the odor to the most likely source before you start cleaning.
| Smell Description | Most Likely Source | First Step to Fix |
|---|---|---|
| Rotten eggs inside drum | Bacteria and biofilm | Empty hot wash with vinegar or cleaner |
| Sulfur near door seal | Moldy rubber gasket | Wipe gasket with vinegar solution |
| Sewage odor at back of washer | Drain hose or standpipe | Check P-trap and hose for clogs |
| Musty smell after cycle | Wet clothes left too long | Remove laundry promptly; leave door open |
How to Clean a Smelly Washing Machine
You don’t need harsh chemicals. Household supplies and a washer-cleaning cycle handle most cases.
Step 1: Run a Cleaning Cycle
Set the washer to its hottest, longest cycle with no clothes. Add two cups of distilled white vinegar directly to the drum, or place a washer-cleaning tablet in the detergent drawer. Run the cycle, then wipe the drum dry with a clean towel.
Step 2: Clean the Gasket and Drawer
Pull back the rubber door gasket and check for trapped items. Wipe the folds with a cloth dipped in equal parts white vinegar and warm water. Remove the detergent drawer, scrub it with an old toothbrush, rinse, and dry before replacing it.
Step 3: Check the Drain Pump Filter
Unplug the washer and locate the small access panel near the bottom front. Place a shallow pan underneath, open the filter, and let any water drain out. Remove lint, hair, and debris, rinse the filter, and screw it back in tightly.
Step 4: Sanitize with Bleach (Optional)
If the vinegar cycle doesn’t remove the smell, run one more empty hot cycle with half a cup of liquid chlorine bleach. Never mix bleach with vinegar or ammonia. Run an extra rinse cycle afterward to remove bleach residue before washing clothes again.
Pro Tip: High-efficiency washers use less water, so residue builds up faster. Clean the machine once a month even if you don’t notice a smell yet.
Top-Load vs. Front-Load Washer Odors
The style of washer changes where bacteria hide and how you clean it.
| Washer Type | Common Odor Source | Best Cleaning Method |
|---|---|---|
| Front-load | Door gasket, detergent drawer | Wipe gasket; run washer-clean cycle |
| Top-load | Agitator base, lid seal, tub | Scrub agitator; soak tub with vinegar |
| High-efficiency | Low-water residue in drum | Monthly cleaning cycle; leave lid open |
Prevent the Smell From Coming Back
A clean washer stays clean only if you change a few laundry habits.
- Use the correct amount of detergent. Too much soap leaves a film that feeds bacteria.
- Switch to powder detergent or high-efficiency liquid if you currently use a lot of liquid fabric softener.
- Remove wet clothes as soon as the cycle ends. Damp laundry left overnight is a leading cause of musty and sulfur smells.
- Leave the washer door or lid open after every load so the interior dries out.
- Wipe the door glass and gasket weekly with a dry microfiber cloth.
- Run a cleaning cycle once a month, or more often if you wash in cold water exclusively.
Warning: If you ever smell natural gas (a rotten-egg odor added by utility companies) near the washer and it isn’t coming from the drum, leave the area and call your gas utility or a plumber immediately. Don’t operate electrical switches.
When to Call a Plumber or Appliance Technician
Some smells point to a problem beyond routine cleaning.
- The odor smells like raw sewage and comes from the drain, not the drum.
- Water backs up into the washer or floor after a cycle.
- The drain hose is kinked, crushed, or installed without an air gap.
- You have cleaned the machine twice and the rotten-egg smell returns within a week.
A plumber can inspect the standpipe, P-trap, and venting. An appliance technician can replace a cracked gasket, a failing drain pump, or a tub seal that’s leaking water beneath the machine.
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Frequently Asked Questions
Why does my washing machine smell like rotten eggs?
Bacteria growing on detergent residue, lint, and moisture inside the drum or gasket release hydrogen sulfide gas, which smells like rotten eggs. Front-load washers and machines that mostly run cold water are the most likely to develop this odor.
Can I use bleach to remove the washing machine smell?
Yes. Run one empty hot cycle with half a cup of liquid chlorine bleach, then run an extra rinse cycle. Never mix bleach with vinegar or ammonia, and don’t use bleach every cycle because it can wear down rubber seals over time.
How often should I clean my washing machine to stop odors?
Clean it once a month with a washer-cleaning tablet or vinegar cycle. Wipe the gasket and detergent drawer every week or two, and leave the door open after each load so the drum dries completely.
Will a new washing machine solve the smell?
Not necessarily. If the odor comes from your drain or standpipe, a new washer will smell the same. Clean the current machine and check the plumbing first before deciding to replace it.
Is the rotten-egg smell dangerous?
The bacterial odor itself is unpleasant but not usually dangerous. However, if you smell natural gas near the washer, treat it as an emergency: leave the area and call your gas utility or a plumber right away.
Conclusion
Keep your washer on a monthly cleaning schedule, wipe the gasket regularly, and leave the door open between loads. If the rotten-egg smell survives two thorough cleanings, call a plumber to check the drain and P-trap before the problem gets worse.