Why Does My Washing Machine Smell Like Rotten Eggs?
Compare hot/cold water, drum odor and standpipe odor before treating the washer.
60-second diagnosis
- Is gas equipment located in or near the laundry area?
- Does the smell appear with hot water, cold water, or only draining?
- Is the odor strongest in the drum or at the standpipe?
- Do other hot-water faucets smell similar?
- Does the smell occur when the washer is off?
Likely causes, ranked by fit
Drain / standpipe sulfur-like odor
CommonBest fit: Odor spikes during pump-out and is strongest behind washer.
How to check: Observe drain stage for gurgling/overflow.
Hot-water source odor
PossibleBest fit: Other hot-water fixtures also smell; cold water does not.
How to check: Compare hot and cold at a nearby faucet.
Washer residue
PossibleBest fit: Drum/gasket smells when idle and plumbing behaves normally.
How to check: Inspect gasket, dispenser and user filter per manual.
Fuel-gas leak
Rule out if plausibleBest fit: Odor is not tied to water/draining and gas equipment is nearby.
How to check: Do not test indoors; leave and call from a safe location.
What to do now
- Rule out gas if plausible.
- Compare hot and cold water elsewhere.
- Separate drum odor from standpipe odor.
- Use the timing of the drain stage to decide between appliance cleaning and plumbing service.
Do not ignite flames, mix cleaners, or repeatedly run the washer if the standpipe is backing up.
When to call a professional
Gas emergency service for suspected gas; plumber for standpipe/drain symptoms; appliance technician for internal leaks or faults.
Questions people ask
Why only on hot cycles?
That suggests the hot-water source deserves attention. Compare hot water at another fixture to see whether the washer is simply revealing a wider water-heater odor.
Why only while draining?
That timing points strongly toward the standpipe/trap/drain system.
Can I fix it with vinegar?
A cleaning product may help some residue odors but cannot repair a missing trap, blocked drain, gas leak or water-heater problem.
- U.S. PHMSA — Recognizing and responding to natural-gas emergencies — Natural gas is odorized and may smell like rotten eggs; PHMSA advises leaving the area and avoiding switches, phones, flames and engines near a suspected leak.
This information is educational and cannot verify a leak, electrical fault, mold condition, water quality result, plumbing-code issue or appliance failure remotely. When there is immediate danger, follow local emergency guidance.