Bathroom Sink Smells Like Rotten Eggs? 6 Fixes for Good
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You lean over the sink to brush your teeth and get hit with rotten eggs. Gross. And confusing, because the sink looks clean.
That smell is hydrogen sulfide, made by bacteria living in gunk you can’t see. The trick is figuring out where the bacteria are hiding. Run through these in order.
Quick Picks at a Glance
| Product | Best For | Deal |
|---|---|---|
| Drain Cleaning Brush (Flexible) | Overflow and pipe walls | Check Price on Amazon |
| Enzyme Drain Cleaner | Breaking down gunk | Check Price on Amazon |
| Plastic Drain Snake | Pulling hair clogs | Check Price on Amazon |
| Water Heater Anode Rod (Aluminum/Zinc) | Hot water only smells | Check Price on Amazon |
Test First: Hot, Cold or Just the Drain?
Fill a glass with cold water and smell it away from the sink. Then a glass of hot. If only the hot water smells, the problem is your water heater (see Fix 5). If neither smells but the drain does, it’s the drain. If all the water smells, it may be your water supply.
Fix 1: Clean the Overflow
That little hole near the top of the basin collects soap scum and bacteria. Scrub it with a flexible drain brush, then pour a mix of baking soda and vinegar into it, wait 15 minutes, and rinse with hot water.
Fix 2: Pull Out the Gunk Under the Stopper
Remove the pop-up stopper (usually a nut behind the drain pipe under the sink) and clean the hair and slime off it. A plastic drain snake pulls out what’s lurking further down.
Fix 3: Clean the P-Trap
Put a bucket under the U-shaped pipe, unscrew the slip nuts by hand, and clean it out. Brace yourself. Reassemble and run water to check for leaks.
Fix 4: Run Water in Unused Drains
If the sink is in a guest bath, the water in the trap may have evaporated, letting sewer gas up. Run the water for 30 seconds once a week.
Fix 5: Hot Water Only? Check the Water Heater
If only hot water smells, bacteria are reacting with the magnesium anode rod in your water heater. Flushing the tank and swapping to an aluminum/zinc anode rod usually fixes it. See our water heater flush guide.
Fix 6: Check the Vent
If you hear gurgling or the smell keeps coming back, the plumbing vent may be blocked, which lets sewer gas escape. Clearing a roof vent is a ladder job many people leave to a plumber.
When to Call a Plumber
Call one if the smell is everywhere, comes from multiple drains, or comes with slow drains throughout the house. Those suggest a vent or sewer line issue.
Keep Reading
Shower Drain Clogged With Hair? · Water Heater Making Popping Noises? · 7 Signs You Need a Water Softener · Garbage Disposal Humming but Not Working?
FAQ
Why does my bathroom sink smell like rotten eggs?
Usually bacteria in the overflow, stopper or P-trap. If only hot water smells, it’s likely the water heater.
Can I pour bleach down the drain to fix the smell?
It can help briefly, but scrubbing out the gunk works better. Never mix bleach with vinegar or other cleaners.
Is a rotten egg smell from the sink dangerous?
Drain odors are usually just unpleasant. If you smell rotten eggs throughout the house, it could be a gas leak. Leave and call your gas company.
Why does only my hot water smell like sulfur?
Bacteria reacting with the water heater’s magnesium anode rod. Flushing and switching to an aluminum/zinc rod helps.
How do I keep my sink drain from smelling?
Clean the overflow and stopper monthly and run water in rarely used sinks weekly.
