Wondering how to unblock a bathroom sink? A blocked bathroom sink doesn’t have to be a huge problem. If your sink has stopped draining, it might be easy to unblock it using items you may already have at home. It’s common for bathroom sinks to get blocked by a build-up of things such as hair, soap, toothpaste, and other debris. Follow our advice below, and you may be able to fix the problem without the need to call a plumber out.
This guide covers everything from first checks to eco-friendly remedies, simple tools you can use, and how to use chemical drain cleaners safely. We’ll also give you some tips to prevent your sink from getting blocked up again.
Why Do Bathroom Sinks Get Blocked?
Blockages don’t usually happen out of the blue. They usually happen because gunk has built up and is causing the flow of water to slow down or stop altogether. It’s not just water that goes down the plug hole. If you want to unblock your sink, you need to think about what might be causing issues.
A blocked sink can be caused by:
- Hair – Particularly long hair ,which can easily get tangled inside the drain.
- Soap scum – Soap and minerals in water combine to create a sticky residue.
- Toothpaste – This hardens inside pipes if not completely rinsed through.
- Skincare & shaving products – Grease from personal care products build up over time. Oily or wax-based products are particularly bad.
- Limescale – In hard water areas, mineral deposits narrow the pipe’s diameter and trap other materials.
- Small objects – Earrings, contact lenses, or broken-off bits of plastic from plugs can easily block the pipe.
In some cases, you may have a blockage further along in the drainage system. If this is the case, you’ll need to call a professional.
Pro Tip: If you live in a hard water area, it might be worth getting a water softener. You could also try descaling your pipes regularly to reduce limescale and soap scum build-up.
Try These Ideas First
Want to unlock your sink? Here’s the good news: lots of blockages are really simple to resolve. Try these simple checks before using tools or pouring anything down the drain:
- Check the plughole: remove hair or debris. Wearing gloves makes this less unpleasant.
- Clean the pop-up plug (if you have one): these often collect a surprising amount of grime just beneath them. Remove and scrub with warm, soapy water and an old toothbrush.
- Check the overflow: The overflow can get blocked up with soap residue. Use an old toothbrush to clean the hole, then flush with a mix of white vinegar and warm water.
Natural DIY Methods to tackle a blocked sink
These often work well for simple blockages and are safe for most plumbing systems.
1. Bicarbonate of Soda & White Vinegar Mix
Using roughly 1 part bicarbonate of soda to 2 parts white vinegar:
- Pour baking soda directly into the plughole.
- Add white vinegar.
- Cover the plughole with a plug or cloth to keep the mixture inside the drain.
- Wait 10 minutes, then flush through with warm water.
The fizzy chemical reaction is great for stubborn blockages.
2. Boiling Water Flush
Boil a kettle and pour the water carefully and slowly into the drain in two to three 30-second stages. This allows time for the heat to do its job.
Warning: Don’t use boiling water if you have PVC pipes or a porcelain sink — use very hot tap water instead to avoid damage.
3. Hot Salty Water Solution
Salt is abrasive and can help scour the inside of the pipe.
Follow these steps:
- Mix 1 part salt to 8 parts hot water — e.g., 120 g salt dissolved in 1 litre of hot water.
- Pour it into the drain and leave it for several hours or overnight.
- Flush with hot water.
4. Biological Washing Powder
- Add three teaspoons of biological washing powder to the plughole.
- Flush with warm water to activate enzymes.
This will also get rid of any nasty drain smells.
Tools for Stubborn Blockages
Try using these simple tools if the natural methods suggested don’t do the trick:
1. Plunger
The suction created by a plunger can shift simple blockages:
- Make sure the overflow is covered by holding a soft cloth over it.
- Place the plunger securely over the plughole and push down firmly.
- Pull the plunger firmly up without removing it from the plug hole.
- Repeat several times.
If the water starts flowing freely, great! It’s working. If not, repeat.
2. Drain Snake or Zip-It Tool
These flexible tools can hook hair and gunk lodged further down.
- Insert the tool into the drain.
- Twist gently to catch debris.
- Pull out slowly — you might be surprised at what comes up!
3. Cable-Tie
- Cut the tip off a long cable tie at an angle.
- Feed it down the drain and wiggle it around to hook objects or hair.
- Pull up slowly.
This is a cheap and surprisingly effective way to remove simple blockages.
4. Clean the U-Bend / Trap
To check if the blockage is local:
- Put a bucket under the U-bend or trap to catch water.
- Carefully and slowly disconnect the pipework.
- Remove debris and rinse before reattaching.
This is often the most effective way to quickly remove a blockage.
5. Chemical Products (Use with Caution)
Chemical drain cleaners can be very effective, but they’re best used as a last resort. Harsh chemicals can corrode pipes over time, and accidental splashes can cause skin or eye irritation. They’re also terrible for the environment.
If you do use them:
- Always wear protective gloves and glasses.
- Open windows to fully ventilate the area you’re working in.
- Never mix different products (dangerous chemical reactions can occur).
Bonus Tip: Choose the right product for the job.
Enzyme-based cleaners are gentler on pipes but don’t use too often as chemicals can cause damage over time.
Time to Call a Plumber
Not all blockages can be fixed using DIY methods.
Seek professional help if:
- Several drains in your home are either draining slowly or are blocked.
- The same blockage recurs frequently.
- There’s a strong sewage smell.
- The bathroom sink starts filling up with water if the toilet is flushed or when other household sinks are used.
If you’re experiencing these issues, it may indicate a deeper problem, possibly in the mains sewage system.
How to Prevent Future Blockages
Once you’ve got your bathroom sink draining well, you’ll want to avoid the problem happening again.
- A drain strainer can help catch objects and hair before they go down the plughole.
- Rinse with hot water weekly to flush away early build-up.
- Avoid pouring oil-based products or large amounts of toothpaste down the drain.
- Clean your bathroom sink regularly — see our guide to easy bathroom cleaning.
- In hard water areas, consider a limescale remover to stop mineral build-up.
- Keep your bathroom fresh and healthy with our tips on how to get rid of mould in your bathroom.
Bonus Tips for Hard Water Areas:
Descale taps, sinks, and drains monthly with white vinegar to reduce limescale build-up. A water softener is a more costly, but effective way to prevent limescale build-up inside pipes and might be worth considering.
Final Thoughts
Unblocking a bathroom sink doesn’t have to be a headache. In most cases, a quick check for debris, a natural remedy, or a simple mechanical method like plunging will do the trick.
Save chemicals for stubborn blockages. If your sink keeps clogging, it might be time to call a plumber to check for more complex issues with the pipework or sewage system.
And remember, tips like using a drain cover and giving your bathroom sink a weekly flush with hot water can keep your pipes clear for longer.
