Quick answer
If a sink smells like rotten eggs, check whether the smell comes from the drain opening, the overflow hole, the garbage disposal, or the water itself. The fix depends on the source: drain biofilm needs cleaning, dry traps need water, and sulfur-like water needs a water-system check.
Search intent this guide answers
This page is built for readers searching: sink smells like rotten eggs, bathroom sink sulfur smell, kitchen sink rotten egg smell. The goal is to give a practical diagnosis first, then safe cleaning steps.
Useful tools
- microfiber cloths
- soft brush or old toothbrush
- dish soap
- gloves
- flashlight
- manufacturer manual when an appliance is involved
Safety first
- Ventilate when cleaning odors or drains.
- Read cleaner labels before use.
- Do not mix cleaners.
- Stop if you see leaks, smoke, gas smell, sewage backup, or electrical issues.
Fast diagnosis table
| What you notice | Likely source | Check first |
|---|---|---|
| Smell from drain when water runs | Biofilm or buildup in drain wall | Brush the drain opening and flush |
| Smell near tiny overflow hole | Bacteria in overflow channel | Clean overflow with small brush |
| Kitchen sink with disposal smells | Food under splash guard | Clean disposal guard and chamber |
| All hot taps smell | Water heater/water supply | Check other fixtures |
Step-by-step fix
1. Smell-test the right place
Run cold water, hot water, then smell near the drain without water. Check the overflow hole separately if the sink has one.
2. Clean the drain rim
Soap, toothpaste, grease and food residue cling to the upper drain. Scrub this visible area before trying stronger solutions.
3. Flush the trap
Run water long enough to refill the trap, especially in guest bathrooms or sinks that are rarely used.
4. For kitchen disposals, clean under the guard
Food splatter hides under the rubber splash guard. Lift carefully and wipe with a brush or cloth.
5. Look for wider plumbing clues
If several fixtures smell or gurgle, the issue is unlikely to be just one dirty sink.
Important warning
Avoid using drain openers as a first step. They can be harsh and dangerous when mixed with other products. Use physical cleaning and water checks first.
Prevention routine
- Fix the source before adding fragrance, sprays or candles.
- Keep wet areas dry and ventilated.
- Clean tools and filters, not just visible surfaces.
- Use the smallest effective amount of cleaner to prevent residue buildup.
- Recheck the same area 24 hours later; recurring odor means the source is still active.
FAQ
Why does my bathroom sink smell when I run water?
Running water can disturb smelly biofilm in the drain or overflow channel.
Why does only hot water smell?
A sulfur-like hot-water smell can come from the water heater or water chemistry, not the sink drain.
How do I prevent sink odors?
Keep the drain rim clean, flush unused sinks weekly, and avoid letting grease or residue build up.