Short answer: Smell the hot and cold taps first. Only the hot water stinks? Likely the water heater. Smell only while the washer drains? The drain trap or pipe.
Drum stinks even when idle? Likely bacteria on residue in the seal, dispenser or filter, and cleaning fixes it.
Standing in a rotten egg cloud right now? Do this.
- Open a window. Hydrogen sulfide gas can be harmful at high levels, Minnesota’s health department says.
- Could it be natural gas? call your gas company right away.
- Hold the bleach. Bleach plus vinegar or ammonia makes a toxic gas.
You lifted the lid at 10 p.m. to start the crate pad, and the smell hit you. Rotten eggs. The puppy backed out of the room.
When a washer smells like rotten eggs, the smell is often hydrogen sulfide, a gas that bacteria make. The drum, the drain and the water heater each make it their own way.
You can find out which by morning, with your nose and a flashlight. If it’s the drain, putting it off makes it worse. One plumbing company warns a drain stoppage will build on itself causing more odors and possible backups.
We sell washer cleaner tablets and a printable puppy schedule kit, and we link to them below.
✓ Built on guidance from Bosch, GE Appliances, In-House Plumbing Company, the Minnesota Department of Health and Poison Control.
Where is the rotten egg smell coming from?
When the smell shows up tells you where it’s made, so start with the timing.
| When it smells | Most likely source | Your test | Fix |
|---|---|---|---|
| Only while the washer runs or drains | The drain: a dry trap, a clog, or a blocked vent | Pull the drain hose out. Does the standpipe smell? | A gallon of water down it. Still smells? Plumber. |
| Even when idle, worst when you open the door | Bacteria on soap, lint and mold in the seal or dispenser | Pull back the seal. Black gunk, a sock, wet fur? | Clean seal, dispenser and filter, then a hot clean cycle. |
| Only in the hot water, washer and taps | The water heater | Smell a hot tap, then a cold one, after hours away. | Anode rod or heater treatment. Usually a plumber. |
| Anywhere, with no washer running | Possible natural gas leak | None. Don’t go looking for it. | Call the gas company right away. |
Mildew, sour or pee smells? See our washing machine smells guide.
Why does my washing machine smell like rotten eggs?
Bacteria make hydrogen sulfide gas. Sulfur bacteria in plumbing and water heaters produce it, the Minnesota Department of Health explains. The bacteria themselves are not harmful. Inside the washer, the likeliest cause is bacteria growing in your washer on dirt, lint and soap.
Cool washes may not make enough heat to kill them, GE adds. A week of crate pads on cold fits that. The smell can also come from the water inlet or a blocked drain system, so test before you scrub.
Why does my washer smell like eggs only when running or draining?
A smell that arrives with the outgoing water points at the drain. Work down this list.
- Test the pipe. Pull the washer out and remove the washing machine hose from the permanent standpipe. If the smell gets worse, that pipe is likely the problem.
- Refill the trap. The trap’s water serves as a barrier preventing sewer gasses from leaking into your house. If it dried out, about a gallon of water should fix it.
- Still smells? Lint, hair, soap or dirt may have built a partial clog that bacteria live on. Clearing it takes a sewer machine and a plumber.
- Check the vent. A clogged roof vent leaves sewer gas nowhere to go but inside. Only go up if it’s safe.
More sewage than egg? Our washer smells like sewer guide goes deeper.
Why does my washer smell like sulfur even when it’s off?
When a front load washer smells like rotten eggs, start at the door seal. A sock sometimes gets trapped behind the seal, stays wet and grows bacteria. Packed puppy fur sits there too. When a top load washer smells like rotten eggs, check the lid seal and dispensers. GE calls dispenser gunk the perfect breeding ground for stinky bacteria.
The 20-minute check
These steps come from GE’s and Bosch’s own repair guides.
- Pull back the door or lid seal. Fish out anything trapped. Hot soapy water and an old rag should be all you need.
- Pull the dispenser. Soak it in hot water and scrub it. Check your manual before using the dishwasher.
- Open the drain pump filter. Cut the power and water, then lay down a towel and a shallow tray. Unscrew the filter cap, clear lint or stray objects, and screw it back tight. Your manual shows where yours sits.
- Run your clean cycle, empty. Use one cleaner your manual allows, never two.
The full scrub is in our how to clean a washing machine guide. Then stop feeding the bacteria. Bosch says to wash regularly at 60° C or higher. End the day with a hot wash and leave the door open, as GE suggests.
Samsung, LG or Whirlpool washer smells like rotten eggs
Step 4 means your maker’s own clean cycle. Each brand names it on its help page.
- Samsung: Self Clean, Self Clean+ or Pure Cycle, about once a month. Bleach goes in the detergent compartment, never straight into the drum.
- LG: TUB CLEAN, run as part of a monthly clean.
- Whirlpool: the Clean Washer cycle, once a month, or when there’s odor. No such cycle? Pick the highest water level and hottest water.
Other brands name theirs in the manual. Smell back two loads after the clean cycle? Clear the pump filter in step 3. Then leave the door and drawer open after every wash, as Samsung advises.
Fur in the seal every week? Our free Pet Hair Removal Finder asks three questions and suggests a type of remover. No sign-up.
A story from Michael Northcutt, our founder: My building’s laundry room is in the basement, down an elevator and a long hallway. A load takes forty-five minutes.
For the first month with our puppy, laundry day was a mess. I’d start the washer, run back up, find her crying in her pen. Run back down to move things to the dryer, run back up, find a puddle.
One afternoon, a neighbor found me in the laundry room on my phone, watching my puppy camera, looking stressed. “You know what I did with my dog?” she said. “Laundry during naps.”
So I changed the order: a potty break, a short play, and then a frozen chew in her pen. That was my window. I wrote a little laundry plan on a card and stuck it to my laundry basket: “Potty, play, chew. Then go.”
Laundry still takes all afternoon. But now it takes all afternoon with no puddles.
Busy laundry days like that are when a wet load sits forgotten in a closed drum for hours.
Why does only the hot water smell like rotten eggs?
Then your water heater is making the gas. The Minnesota Department of Health says a heater can produce hydrogen sulfide gas in two ways. It keeps sulfur bacteria warm, and its magnesium anode rod feeds the reaction. Fixes include a new or removed anode, a chlorine bleach flush, or the heat treatment below. Raising the temperature can be dangerous, it warns.
How hot each fix needs to be
Unless you know water heaters well, have a plumber or water system professional do the work. Lower the thermostat afterward.
City water or well water: does it change the fix?
Run the same tap test either way. The health department lists the water heater as its own source, separate from the well. On a well, a smell at the cold taps too likely means the well or plumbing. A licensed well contractor can disinfect both with a strong chlorine solution.
The smell usually does not relate to the sanitary quality of the water. To be safe, test well water for coliform bacteria and nitrate.
Why do my clothes smell like rotten eggs after washing?
The clothes picked the smell up from the water or the drum. Smell the hot tap first. If it stinks, treat the water heater before you rewash anything.
Clean taps point back to the drum. Bosch says constant cool washes with small detergent doses can lead to unpleasant smells in the machine or your laundry. Do the 20-minute check, then rewash. Our clothes smell like mildew after washing guide covers the rewash.
Vinegar, bleach or a washer cleaner?
| Source | Their advice | Where they differ |
|---|---|---|
| Bosch | Wash at 60°C or higher, dose detergent right, use its tested washing machine cleaner | No vinegar or bleach mentioned |
| GE Appliances | A washer cleaner, or baking soda in the dispenser and two cups of white vinegar on a hot cycle | Vinegar is fine |
| In-House Plumbing Company | Wipe the seal with half vinegar, half water, or bleach; then a hot cycle with baking soda and vinegar | Vinegar or bleach, your pick |
| Maytag, in our hub guide | No vinegar in the drum, the acid can wear seals and hoses | No vinegar. See the vinegar section |
The sources split on vinegar, so go with your manual. If it allows vinegar, GE’s method is fine. If not, use a washer cleaner, one product per cycle.
“Mixing bleach with an acid forms chlorine gas.”
Wendy Klein-Schwartz, Pharm.D., MPH, clinical toxicologist, writing for Poison Control
Puppy safety: Poison Control says to store bleach up, away and out of sight of children. Same shelf for puppies. Breathed fumes? Get fresh air and call 1-800-222-1222.
When should you call a plumber?
Call one when the smell starts past the drain hose or comes in with the water.
- The standpipe still smells after a gallon of water. Have a plumber check that the trap and drain pipe were installed right. A clog takes a sewer machine.
- Only the hot water smells. That’s water heater work.
What should you do this week?
Tomorrow morning, before anyone runs water, smell the hot and cold taps. Then do the standpipe test and the 20-minute check.
Rotten egg washer smell FAQ
Why does my washer smell like rotten eggs after sitting unused?
The drain trap may have dried out, letting sewer gas up the standpipe. One plumbing company suggests pouring about a gallon of water down the pipe.
Can I pour bleach down the washer drain to kill the smell?
Not on top of another cleaner. Poison Control says bleach plus an acid, including vinegar, forms chlorine gas, and bleach plus ammonia forms chloramine gas. GE suggests vinegar and baking soda for the drainpipe instead, so pick one.
Do washer cleaner tablets get rid of a rotten egg smell?
Only when it’s grime and soap residue inside the drum and seal. Our product page says a cleaning cycle may not solve every source of odor. A drain trap, sewer line or water heater needs its own fix.
How we put this together: In October 2026 we read Bosch, GE Appliances, In-House Plumbing Company, Minnesota’s health department and Poison Control. We checked cycle names on Samsung, LG and Whirlpool help pages, plus page one of Google and owners’ forum posts. Nobody at LoveMyPuppy is a plumber.
Sources
- Bosch: What should I do when my washing machine smells of rotten eggs? and Cleaning a washing machine filter
- GE Appliances Factory Service: Why does my washing machine smell?
- In-House Plumbing Company: Why Your Washing Machine Smells Like Sewage or Rotten Eggs
- Minnesota Department of Health: Why Does My Water Smell Like Rotten Eggs? Hydrogen Sulfide and Sulfur Bacteria in Well Water
- Poison Control (National Capital Poison Center): Chlorine gas: What happens if you mix bleach and other cleaners