Function and Cleaning of a Sink Overflow Hole

clean your sink overflow hole If you’ve ever taken a good look at the back of your bathroom sink, you’ve noticed that there’s a small hole underneath the faucet and toward the back of the bowl. That’s the overflow hole in your sink and most people don’t give it much thought.

However, it’s important to know how this little bit of negative space functions so that you can keep your bathroom sink clean and clear. Learn how to clean the bathroom sink overflow hole with the following tips.

First Things First: What is the Overflow Hole in Your Sink?

The overflow hole is aptly named, as it keeps your sink from flooding. It does this by diverting water, giving you more time to act before the contents spill over if you or someone in your household accidentally leaves the faucet on or if you have a plumbing issue.

Keeping the Overflow Hole in Your Sink Clear

As you can imagine, it’s pretty important to keep the overflow hole in your sink from getting blocked. Otherwise, it can’t do its job. You also need to keep it clean. After all, the bathroom is a hot damp place and the last thing you want is to find out you’re growing mildew or mold in the bathroom sink overflow drain.

You’ll need:

  • A sink-cleaning brush or pipe cleaner
  • A funnel made of a material like silicone that can withstand the temperature of boiling water and doesn't easily conduct heat
  • Two to three quarts of boiling water

  1. Stick the pipe cleaner or sink-cleaning brush into the overflow hole.
  2. Push the brush in and out several times to remove as much gunk and buildup as possible.
  3. Bring the water to a boil.
  4. Stick the funnel in the overflow hole in your sink.
  5. Slowly pour the boiling water through the funnel to loosen and flush any remaining buildup. (Be careful! You don’t want to splash yourself with boiling water and steam can give you a nasty burn, too! It may be a good idea to call in a helper here.)
  6. Repeat as needed.

How to Clean the Bathroom Sink Overflow Hole if it Stinks

If mildew happens to build up in the overflow hole in your sink, you’re going to be left with a very nasty smell. Hopefully, your bathroom sink will never get to that point, but if it does you need to know how to tackle the stench.

You’ll need:
  • 1 cup of baking soda
  • 1 cup of distilled white vinegar
  • Two quarts of boiling water
  • A funnel made of a material like silicone that can withstand the temperature of boiling water and doesn't easily conduct heat

  1. Stick the funnel in the overflow hole in your sink.
  2. Pour the baking soda down the funnel.
  3. Next, slowly pour the vinegar down the funnel. Be prepared, it will fizz a little.
  4. Let this sit for about 15 minutes so the baking soda and vinegar can work their deodorizing magic.
  5. Carefully flush the sink with the boiling water. Work slowly so you don’t splash yourself or get a steam burn. Don’t be afraid to ask for help.
  6. Repeat as needed if the odor remains.
As you can see, checking and cleaning the overflow hole doesn’t take a great deal of time, but it can make a huge difference in the functionality of your sink. Additionally, it can keep your bathroom from having a musty odor.

Need more tips for busting bad smells? Check out these instructions for cleaning a stinky kitchen sink. And if you just don’t have a spare minute to keep your bathroom clean, contact your local Merry Maids. We’re happy to lend a hand so you can spend more time doing the things you love.