How to Clean a Smelly Sink Overflow Hole
A musty or sewer-like smell from the sink that you cannot place often comes from the overflow holes, the small openings near the top of the basin. They connect to a hidden channel that collects gunk and rarely gets cleaned. Flush and brush them out, and the smell clears.
We make small-batch beeswax candles in Far Rockaway, so a room that truly smells clean is our whole focus, and that always starts at the source rather than the scent. Below is where the smell comes from, how to clear it step by step, and how to keep the space fresh afterward, with the full the MBur beeswax candle collection here as you read.
Why the overflow smells
The overflow opening routes excess water down through an internal channel to the drain, and soap, skin, and toothpaste residue coat that channel over time. It is dark, damp, and never scrubbed, so it grows a bio-slime.
That slime is the smell, and it drifts back out of the holes whenever water runs. A quick clean of the visible drain never reaches it.
How to clean it, step by step
- Find the overflow. Locate the hole or holes near the top rim of the sink basin.
- Flush it with baking soda and vinegar. Pour baking soda into the overflow, using a small funnel, then vinegar, let it foam, and flush with hot water.
- Brush the channel. Work a small bottle brush or pipe cleaner into the overflow to scrub the hidden channel. A flexible brush reaches further.
- Disinfect. Follow with a diluted bleach or more vinegar to kill the slime, then flush again.
- Repeat if needed. Heavy buildup may take a second round to fully clear.
The overflow is the spot almost everyone forgets. Cleaning it along with the drain is what finally clears a smell you could not trace.
Keep it from coming back
Flush the overflow monthly when you clean the drain, and wipe the basin rim where residue collects.
A quick baking soda and hot water flush keeps the channel from building up slime again.
Freshen the whole room once the source is gone
With the overflow gunk handled, the air itself is the last step. A clean candle is the finishing touch here, best lit once the space is already clean. From there it is the fastest way to make the room read fresh rather than merely neutral.
For your bathroom, Sunday Reset fits well. It is cool and clearing, with peppermint, eucalyptus, and grapefruit, and like every MBur candle it is poured from 100% beeswax with a wooden wick and phthalate-free non-toxic fragrance oils, so freshening the air never means adding soot on top.
Frequently asked questions
What are the little holes near the top of my sink?
The overflow, which drains excess water and helps air the drain. It connects to a hidden channel that collects residue and can smell.
Why does my sink smell even though the drain is clean?
The smell is often in the overflow channel, not the main drain. Flush and brush the overflow to clear it.
How do I clean the overflow hole?
Flush it with baking soda and vinegar, then scrub the channel with a small bottle brush or pipe cleaner and disinfect.
How often should I clean it?
About once a month, along with the drain, keeps it from building up.
Ready to keep your space smelling clean once the source is handled? Explore the MBur beeswax candle collection and find the scent that fits the room.
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