A  Guide to Clean the Overflow Hole in a Bathroom Sink

Washing your bathrooms must be a daily routine for many. From scrubbing down the toilet, cleaning the basin, and making sure the entire area looks clean and fresh. However, despite the deep cleaning, many people often ignore one tiny yet vital sink feature. This is the overflow hole in the bathroom sink.

A sink is an integral part of every bathroom. You must be using high-quality products to get rid of any buildup in the drain or mold from the surface of the faucet. Extra time must be spent ensuring that no stains remain on your sink. This is because it can deteriorate the overall look of the restroom.

Regardless of how your bathroom looks, if you miss cleaning the overflow hole, you have not justified the cleaning process. Many people do not even know the actual purpose of this underrated feature. However, it is an integral part of every basin that serves a meaningful purpose. Hence, it is pivotal to clean it regularly. Go over this article to find out how.

What is Overflow Hole in a Sink?

This tiny feature is present on the sink, underneath the faucet. It is not just an ordinary design to enhance your washbasin’s beauty. But it performs a very important task.

Many people wonder whether the bathroom sink needs an overflow hole. The answer, in short, is yes. The hole protects your basin from getting overflowed. It prevents water from spilling out and going all over the floor in case the basin fills up to the maximum capacity. Be it someone’s forgetfulness to close the taps properly or any plumbing issue, it is possible to cause overfilling. In such times, this design serves as a drainage and saves you from a great mess.

This additional drainage opening is located a few inches down the maximum capacity of the basin. Apart from its incredible drainage function, it also helps the sewer system. It allows air to pass through the sewer, making a form of suction. This suction is what causes water to flow down the drain at a faster pace.

Water must drain quicker than the amount that runs down the faucet. The drainage feature helps ensure this so that you do not face any problems with the drainage mechanism. It also prevents clogged pipes and back-flow of dirty sewage water, hence, protecting your entire home.

The Need for Cleaning the Overflow Holes

As mentioned earlier, you must clean this part of the basin regularly. But what is the need to do so?

With constant use of the sink, it is normal for dirt, debris, and mold to accumulate in the tiny openings. This often leads to a buildup of grime that gets worse with time. The amount of dirt and other particles that attach to the inner walls and surfaces becomes dried and solidified. This acts like a petri-dish, harboring various bacteria, viruses, and other microorganisms, injurious to human health.

Here are some of the main causes of a dirty drain opening.

Dust and Debris

The air in the atmosphere carries a lot of dust and micro-particles. They find their way down the hole and accumulate over time.

Food and Waste

Be it washing dishes or hands, food and organic waste particles can also lodge in this tiny compartment of the basin. It can further rot, leading to a bad odor and other unhygienic conditions.

Bath Products

Different bath products like shampoo, conditioner, handwash, facewash, etc. have certain oils and chemicals in them. These often go into the opening and accumulate over time. This could result in getting the overflow drain in the bathroom sink clogged.

Heavy Mold

Moist, warm, and dark places are a mold’s best friend. These tiny pits provide an ideal condition for mold and mildew colonies to live. The fact that it is such a hard place to reach allows the microorganisms to thrive without getting disturbed. The resultant bacteria and various disease-causing microbes can be fatal to your health. They can cause allergic reactions and other harmful diseases if not gotten rid of. The mold build-up could be another reason why your overflow hole in the bathroom stinks.

Hence, it is essential to pay attention to cleaning this sink feature.

How to Keep the Sink Overflow Hole Clean and Clear?

To ensure a hygienic bathroom, it is important to pay attention to the minor details. Hence, you must keep the sink drain opening clean, clear, and clog-free at all times. You should also clean the overflow drain in the bathroom sink regularly.

This would not only prevent your basin from getting overflowed and spilling everywhere. But it would also ensure that your sewer system remains clean and without any blocks or build-up.

Things You Will Need

Here are the materials required:

  • Thin brush or pipe Cleaner
  • Silicone or metal funnel
  • Boiling water

Steps to Maintain a Clear Overflow Hole

For good maintenance of this important sink feature, follow these few simple steps.

Loosen the Gunk

Take a thin brush or pipe cleaner and insert it into the opening. Move the brush to and fro several times, using a little force if needed. Use a rotatory motion as well to cover all internal sides and surfaces. This will help remove a lot of accumulated dirt, debris, and gunk.

Prepare Hot Boiling Water

Next, fill a jug with hot, boiling water. If your faucet can run extremely hot water, you can fill the jug directly with it. If hot water is not available, boil some water in a kettle or on the stove.

Attach the Funnel

Fix the funnel inside the opening. Make sure the funnel you use can withstand the temperature of boiling water. It is preferred to use a silicone funnel. It will not melt nor get deformed while pouring the hot water through it.

Pour Boiling Water

Finally, pour the boiling water through the funnel and down the hole. The hot water will melt away any residual gunk that may be left behind even after cleaning with a brush. This shall make this sink’s feature clean, clear, and fresh.

 Make sure to do this step slowly and carefully. This is to ensure no hot water splashes your way as it can lead to severe burns and injuries.

Repeat if Needed

If you still think there is some build-up left, feel free to repeat these steps.

How to Clean a Smelly Sink Overflow Hole?

How to Clean a Smelly Sink Overflow Hole

If you have not cleaned the small pit present on the basin regularly, you will experience some nasty odor. This is due to the growth of mold and mildew colonies in this small, dark, humid, and moist area.

These microbes emit a pungent and stinky smell over time. This is not only unhygienic but can cause your entire bathroom and even your house to smell. Therefore, you must clean this sink’s feature immediately and get rid of the smell.

Things You Will Require

Here are the things you shall need for cleaning.

  • Distilled white vinegar
  • Baking soda
  • Hot water
  • Silicone or metal funnel
  • Thin, flexible brush or drain brush

Steps to Clean the Overflow Hole

You might think that the worse condition of this sink’s feature would be impossible to fix without professional help. But this is far from the truth. Using some basic household tools along with a few easy steps can get the work done within minutes.

Here are the steps you need to follow.

Place the Funnel

First, attach the funnel to the opening. Make sure that you use silicone or a metal funnel for this cleaning project. This is to ensure that the funnel can withstand the hot temperature of the water you will later pour through.

Pour Baking Soda and Vinegar

Next, take one cup of baking soda and pour it down the hole through the funnel. Follow this with a cup of distilled white vinegar. Make sure to pour the vinegar down slowly since the reaction of the two would cause a fizz.

The fizzy reaction that occurs is important to clear the gunk and build-up. This is because it creates an acidic medium in the inner surface of the basin. The acidic environment helps loosen the debris and gunk, making it easier to scrub out.

Vinegar and baking soda also act as natural deodorizers. Hence, their combination is used to eliminate the pungent, nasty odor from the drainage system.

Note that is important to use distilled white vinegar for this step. Do not use any other kind of colored vinegar such as apple cider vinegar or red wine vinegar. This is because it would cause stains on the surface of the basin that are hard to remove.

Scrub the Surfaces

Allow the vinegar and baking soda mixture to sit for approximately 20 to 30 minutes. Then, using a thin, flexible pipe brush or drain brush, scrub the inner surfaces and corners of the drainage pit. Make sure to slide the brush as deep as you can, moving in a to and fro motion. Twist and rotate the brush as well for greater and more efficient cleaning.

Prepare Hot Water

Get some hot water from the faucet into a jug. If you feel your water from the tap is not hot enough, boil it on the stove or in a kettle and keep it ready.

Pour the Hot Water

Next, pour the hot or boiling water through the funnel and into the drain. This would get rid of the vinegar and baking soda mixture as well as get rid of any residual build-up.

Make sure to pour the hot water slowly to prevent any splash-backs.

You should avoid this step in case your sink is not made from materials like stone, ceramic, or porcelain. This is because the hot water could damage the surface and integrity of the basin.

Repeat if there is Need

If you think there is still odor or gunk left behind, feel free to follow these steps again.


Do not pour very hot water if working with plastic or resin sinks. You can use warm water to pour down the drain pit. This will not only get the work done but also make sure the basin does not get damaged.

Some drain holes are covered with caps or stoppers. These are provided by the manufacturers to allow users to control the amount of water they want to fill. Read the instructions provided by the manufacturer before removing the cap for cleaning.

You can apply the vinegar and baking soda mixture on the cap and stopper as well. Scrub it down using the brush to get rid of any grind, stains, and mold. Rinse it with clean water and allow it to dry completely. Finally, place it back over the drain pit as mentioned in the manufacturer’s instructions.

Other Methods of Cleaning an Overflow Hole

Other Methods of Cleaning an Overflow Hole

The methods mentioned above are a great way to maintain the cleanliness of the drain pit. But it is no harm to learn some quick and easy methods as well.

Clean with Zip Ties

Zip ties are a great way to clean the drainage holes. They are not only thin, long, and flexible but are also quite strong and sturdy.

Insert the zip tie down the opening. Make sure to reach as deep as you can to cover the maximum surface area. Move the zip tie in an up and down, and to and fro motion. This will help loosen the internal build-up.

Next, pour some hot water down the drain. This shall eliminate any hard and stuck residues that may be present.

Clean with a Rubber Hose

A similar method used to clean the overflow pit is using a rubber hose. Cover the drain of the basin using a rubber plug. Then turn on the faucet and allow the water to run for a few minutes until the basin drains.

As it overflows, water shall be going down the drainage pit. At this time, take the rubber hose and insert it into the opening.

Blow in large amounts of air into the drainage channel. Continue doing so until you feel the air is flowing in smoothly. This will indicate that the channel is clean and clear of any dirt, debris, and gunk.

Final Thoughts

Regular cleaning and maintenance of the sink overflow hole can help save you a lot of trouble and hard work. Not only is it important to keep it clean for the smooth functioning of the sink. But it is also necessary to maintain good hygiene in your bathroom. Therefore, cleaning it regularly ensures added life to the basin and also protects your home sewerage system from getting clogged. This would save you a lot of time, energy, and finances in the future.