How to Clean A Pedestal Sink Overflow

Jessica Stone
by Jessica Stone

Have you ever taken a moment to inspect the back of your pedestal sink and noticed the small hole underneath the faucet? This small hole is referred to as an overflow hole and generally goes unnoticed, but you need to clean a pedestal sink overflow. The purpose of the overflow hole is to provide ventilation and collect any excess water that could cause your sink to spill over.

To clean a pedestal sink overflow, insert a funnel into the overflow hole, and pour 1 cup of baking soda down the funnel. Let it sit for 1-2 minutes, then slowly pour in 1 cup of white vinegar and let sit for 15 minutes. Finally, flush out the overflow hole with 2 quarts of boiling water to clear out the solution and debris.

Depending on your individual sink model, you may have more than one of these useful drainage holes. There are several different methods for keeping your overflow hole clear of dirt, bacteria or any other debris. Let’s explore all of the possible ways for how to clean your pedestal sink’s overflow hole.

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What is an Overflow Hole?

The overflow hole is an essential part of any pedestal sink that is very often ignored by homeowners. These small openings will generally be located in either on the wall of basin nearest to you or directly under the sink’s faucet. Your sink may have one, two, or none at all.

Essentially, the overflow hole on your pedestal sink serves two purposes: to introduce air into the system to allow for faster drainage and prevent your sink from overflowing. For example, if the water is ever left on while the stopper is closed, the overflow hole will channel water down into it rather than allowing water to spill out and onto the bathroom floor.

The sink overflow system often involves a hidden channel that runs underneath the sink basin. The overflow hole is at the top of the channel and on the bottom, there is an outlet hole that drains into a drain below the basin. Consequently, the overflow hole and basin drain into the same pipe, but the overflow is not affected by the sink’s stopper.

How to Clean a Pedestal Sink Overflow

Now that you understand the purpose of an overflow hole, you know how essential it is that it stays clear in order for it to function properly. Gunk can collect near the bottom of the overflow channel and reduce the flow of both water and air. Also, since the overflow hole generally doesn’t get flushed out unless the water reaches high enough, it doesn’t get a steady cleaning.

Additionally, since bathrooms are notoriously damp and hot places, you want to ensure that the overflow hole is clean to prevent any possible mold or mildew growth.

Ways To Clean A Pedestal Sink Overflow Manually

The following are some of the ways that you can effectively clean the overflow hole in your pedestal sink manually:

  • Plastic zip ties. Using plastic zip ties are a great way to dislodge any buildup in the overflow hole. Make sure that the zip ties are long and rigid enough to successfully remove any blockages. Simply move the zip tie up and down to loosen and release and gunk in the channel. However, use special care to avoid dropping the zip tie and getting it stuck in the overflow hole.
  • Pipe cleaner or sink-cleaning brush. Similar to the zip ties, insert either a pipe cleaner or cleaning brush into the overflow hole. Push it in and out several times to displace as much buildup as possible.
  • Rubber hose. Fill the sink with water so that it is slightly higher than the overflow hole. Allow some of the water to run down into the channel and put one end of a rubber hose over the opening of the hole. Taking the other end of the hose, blow air through the hose, drain the sink and then repeat blowing puffs of air into the tube. When the overflow hole is clear, the air should blow through without any resistance.
  • Funnel or tubing. Stick a funnel or tubing, that is made out of heat resistant material, into the overflow hole. Pour boiling water through the funnel or tube to flush any remaining debris out of the overflow channel. For best results, this step should be done alongside one of the steps above.

Using an Enzyme Eater to Clean Sink Overflow

If you’ve noticed an unpleasant odor in your sink, it’s possible that bacteria have grown inside the overflow. If this is the case, boiling water will not be effective at removing the smell or killing the bacteria.

Enzyme drain cleaners are designed to eat away at organic bacteria and rid the sink of its undesirable stench. These cleaners can be purchased at your local home improvement center and will often come in either a powder or liquid form. The liquid kind will be ready to go but the powder will require some mixing before application.

Using a funnel, pour the enzyme mixture into the overflow hole and let it sit overnight. This will allow the enzyme cleaner to do its magic and eradicate the bacteria. In the morning, flush the overflow hole with clean, warm water.

Quick Tip: When choosing an enzyme cleaner, make sure that you select carefully if you’re on a septic as you want to ensure that the enzyme cleaner is safe for these types of drains. Enzyme cleaners will not damage your pipes and will actually help to replenish the good bacteria in your septic tank.

Vinegar and Baking Soda for Your Overflow

Another, more DIY, way to deep clean your overflow hole and channel is by using some household materials that you may already have on hand. Vinegar and baking soda combine to create a cleaning, foaming, and deodorizing mixture that cleans your overflow hole without using any potentially harmful chemicals.

Using a funnel, insert it into the overflow hole and start by pouring 1 cup of baking soda into the funnel. Give it a moment to settle then gradually add 1 cup of distilled white vinegar right on top. This solution will create a foaming reaction and filter down into the drain.

Wait about ten minutes for the mixture to sit inside the overflow hole and do its cleaning. After the time is up, pour boiling water into the overflow hole to both flush out the cleaning solution and help sanitize the drain.

Wrapping It Up

If you have an overflow hole in your pedestal sink, it’s important that it is kept clean and free of debris. Should your sink drain ever become clogged, the overflow’s job is to prevent water from overflowing out the sides. It also helps improve drainage by allowing air to enter the drain pipe through the overflow channel.

To ensure that your sink’s overflow can perform its’ job properly, you need to perform regular maintenance on it and keep it clean. This is especially true since the overflow doesn’t ever get flushed out unless your sink is overflowing. You have a number of options to choose from to effectively clean your pedestal sink overflow.

Whether you choose to go with an enzyme eater or baking soda and vinegar, you will allow the overflow to serve its purposes efficiently.

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Related Questions

Are overflows required on bathroom sinks?

No, bathroom sinks are not required to have an overflow hole or overflow system. However, they are a great way to help improve overall drainage speed and reduce the risk of your sink spilling over onto the floor.

Why does my bathroom sink overflow smell?

If you detect a foul smell coming from the overflow in your sink, it’s likely harboring bacteria, mildew, and gunk. Just the buildup of mildew is enough to make the area around your sink’s overflow stink. To get rid of the smell, combine ½ cup of baking soda and ¼ cup of table salt. Pour this scouring mixture into the hole and follow it up with one cup of warm distilled vinegar. Let is settle for about 15 minutes before rinsing it down with hot water.The vinegar’s purpose is to disinfect while the baking soda and table salt scour. Together, they will leave your overflow hole sanitary and free of undesirable smells.

Can you use bleach to unclog a drain?

Using bleach in your drain along with hot water can help deodorize it and kill any germ causing bacteria. However, bleach does not contain any active ingredients that will eat away at the material clogging your drain. Instead, use a baking soda and vinegar mixture or enzyme cleaners to unclog a drain. However, if you have a septic system you should never use bleach in the drain or the overflow.

Can Coke really unclog a drain?

As strange as it sounds, both Coke and Pepsi contain phosphoric acid which can breakdown gunk that may be clogging your drain. Take a two-liter bottle of either soda brand and allow it to reach room temperature. Pour the entire bottle down the drain that is clogged and let it sit for at least an hour (longer for more intense clogs). Afterward, flush the drain with boiling water to clear it!

Jessica Stone
Jessica Stone

Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.

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