Unblock Your Sink: DIY Guide for Kitchen & Bathroom

By The FixDelivered Team · Updated 2026-07-05 · 7 min read

A blocked sink is an all-too-common household nuisance, whether it's in your kitchen or bathroom. It can disrupt daily routines, create unpleasant odours, and if left untreated, potentially lead to more significant plumbing issues. The good news is that many sink blockages can be cleared effectively with a few simple DIY methods and common household tools. This guide will walk you through the practical steps to tackle a stubborn sink blockage yourself.

Why Does My Sink Block?

Understanding the common culprits behind a blocked sink can help you prevent them and identify the likely cause of your current issue:

Kitchen Sinks: Typically suffer from a build-up of food debris (especially coffee grounds, rice, pasta), cooking fats, oils, and grease. When these cool, they solidify and cling to pipe walls, trapping other waste.
Bathroom Sinks: Often get clogged with hair, soap scum, toothpaste residue, and small foreign objects like cotton buds or dental floss. Soap scum and hair combine to form tough, sticky blockages.

Before You Start: Safety First!

Before attempting any DIY plumbing, always prioritise safety:

Protect Yourself: Wear rubber gloves to protect your hands from grime and chemicals. Eye protection is also advisable, especially when dealing with splash-back or using chemical solutions.
Ventilation: If using any commercial drain cleaners (though we recommend safer alternatives first), ensure the area is well-ventilated.
Never Mix Chemicals: Do not mix different chemical drain cleaners, or chemical cleaners with home remedies like vinegar and bicarbonate of soda. This can create dangerous fumes or explosive reactions.
Hot Water Caution: Be careful when handling boiling water to avoid scalds.

What You'll Need

Gather these items before you begin:

Rubber gloves and eye protection
Kettle or saucepan for hot water
Washing up liquid
Plunger (cup-style for sinks)
Bicarbonate of soda (baking soda)
White vinegar
Bucket and old towels
Adjustable spanner or pipe wrench
Torch (optional, for inspecting the trap)
Drain snake or plumbing auger (for tougher clogs)

DIY Methods to Unblock Your Sink

Method 1: Boiling Water and Washing Up Liquid

This is the simplest and often most effective first step for grease-related clogs.

Remove Standing Water: If there's standing water in the sink, carefully scoop out as much as you can.
Pour Washing Up Liquid: Pour about half a cup of washing up liquid directly down the drain.
Add Boiling Water: Carefully pour a full kettle of boiling water down the drain. The washing up liquid helps to break down grease, and the hot water helps to melt it.
Wait and Flush: Wait 20-30 minutes, then flush with hot tap water for a few minutes. Repeat if necessary.
Caution: Do not use boiling water if you have PVC pipes that are old or known to be brittle, as extreme heat can damage them.

Method 2: Plunger Power

A good quality plunger can create significant pressure to dislodge clogs.

Fill Sink with Water: Fill the sink with enough hot water to cover the bell of the plunger. This helps create a good seal.
Seal the Overflow: If your sink has an overflow hole, block it tightly with a damp cloth or a helper's hand to ensure maximum suction.
Position the Plunger: Place the plunger firmly over the drain opening, ensuring a tight seal.
Plunge Vigorously: Pump the plunger up and down with short, sharp strokes for about 20-30 seconds, maintaining the seal.
Break the Seal: Quickly pull the plunger away from the drain. You should hear a suction sound.
Check and Repeat: If the water drains, flush with hot water. If not, repeat the process several times.

Method 3: Bicarbonate of Soda and Vinegar

This natural remedy creates a fizzing reaction that can break down soft clogs.

Remove Standing Water: Clear any standing water from the sink.
Pour Bicarbonate: Pour one cup of bicarbonate of soda down the drain.
Add Vinegar: Follow with one cup of white vinegar. The mixture will begin to fizz immediately.
Cover and Wait: Quickly cover the drain opening with a stopper or a damp cloth to contain the reaction and direct it downwards.
Wait: Let it sit for at least 30 minutes, or preferably overnight for stubborn clogs.
Flush: Flush the drain thoroughly with hot tap water.

Method 4: The Drain Snake (Auger)

For deeper or more stubborn clogs, a drain snake (also known as a plumbing auger) can be highly effective.

Prepare the Area: Place a bucket and old towels under the sink to catch any drips or debris.
Insert the Snake: Feed the end of the snake into the drain opening. If it's a kitchen sink, you might have better access by removing the P-trap first (see Method 5).
Advance the Snake: Push the snake down the pipe until you meet resistance.
Rotate and Push: Once you hit the clog, crank the handle to rotate the snake. This allows the coil at the end to break up the blockage or hook onto it.
Withdraw the Snake: Slowly pull the snake back out, carefully wiping any debris into your bucket.
Flush: Flush the drain with hot water to ensure it's clear.

Method 5: Cleaning the P-Trap

The P-trap (or S-trap in older installations) is the U-shaped pipe directly beneath your sink. This is where many clogs often reside.

Prepare: Place a large bucket directly under the P-trap to catch water and debris. Lay down old towels for extra protection.
Loosen Nuts: Using an adjustable spanner, carefully loosen the slip nuts on both ends of the P-trap. These are usually plastic or brass.
Remove Trap: Gently remove the P-trap. Be prepared for a small amount of water to spill.
Clean the Trap: Inspect the trap for blockages. Remove any hair, grease, or debris with your gloved hand or an old brush. You can also rinse it thoroughly under a tap.
Check Pipes: Use a torch to look up the drainpipe towards the wall and down the tailpiece from the sink to check for any remaining blockages. A drain snake might be useful here if you see anything.
Reassemble: Reattach the P-trap, ensuring the slip nuts are hand-tightened first, then gently snugged with the spanner. Do not overtighten, as this can crack plastic pipes.
Test for Leaks: Run water into the sink and check for any leaks around the P-trap connections. Tighten slightly if necessary.

When to Call a Professional Plumber

While DIY methods can resolve many blocked sinks, there are times when professional expertise is essential. You should call a plumber if:

The blockage persists after trying several DIY methods.
Multiple drains are slow or blocked (e.g., sink, shower, toilet), indicating a potential main drain issue.
You notice foul odours or sewage backing up into your sink or other fixtures.
You lack the confidence or tools to tackle the job yourself.
There's a risk of damaging your plumbing system.

Attempting complex plumbing repairs without the right knowledge or tools can often worsen the problem, potentially leading to costly damage. For reliable, vetted local plumbers who can quickly diagnose and fix stubborn blockages, you can tell us your emergency at FixDelivered. Our service ensures you get help fast, with transparent pricing agreed upfront.

As a rough guide for 2026, a professional plumber might charge anywhere from £80 to £150 for a standard call-out to clear a blocked sink, depending on the complexity of the clog and your location in the UK. Emergency call-outs outside of normal working hours will typically be higher, potentially ranging from £150 to £250.

Preventing Future Sink Blocks

Prevention is always better than cure. Here are some tips to keep your sinks flowing freely:

Use Drain Covers: Place mesh drain covers over plugholes to catch hair and food particles before they enter the drain.
Dispose of Grease Properly: Never pour cooking fats, oils, or grease down the sink. Let them cool and solidify, then scrape them into the bin.
Scrape Plates: Scrape food scraps into the bin before rinsing dishes.
Regular Hot Water Flush: Periodically flush your kitchen sink with hot water (not boiling) to help prevent grease build-up.
Bicarbonate and Vinegar Flush: Perform a monthly bicarbonate of soda and vinegar flush as a preventative measure.
Avoid Harsh Chemical Cleaners: While tempting, these can be corrosive to pipes and harmful to the environment. Stick to the methods outlined above.

Dealing with a blocked sink can be frustrating, but with the right approach, many common clogs can be resolved without needing a professional. By understanding the causes, implementing simple DIY techniques, and maintaining good habits, you can keep your drains clear. However, for those stubborn blockages or when in doubt, remember that expert help is readily available. FixDelivered helps you find a local plumber quickly and efficiently, ensuring your plumbing issues are resolved by a trusted expert.

Frequently asked questions

Can I use chemical drain cleaners to unblock my sink?

While readily available, chemical drain cleaners can be harsh. They often contain corrosive substances that can damage your pipes over time, especially older ones, and are harmful to the environment. They can also be dangerous if mixed with other chemicals or if they splash back. We recommend trying the natural and mechanical methods outlined in this guide first, as they are generally safer and more effective for common clogs.

How often should I clean my P-trap?

It's a good idea to inspect and clean your P-trap every 6 to 12 months as a preventative measure, especially if you notice your sink draining slowly. Of course, if you suspect a clog is located there, you should clean it as part of your unblocking efforts.

What's the difference between a P-trap and an S-trap?

Both are U-shaped pipes designed to hold water and create a seal that prevents sewer gases from entering your home. An S-trap forms an 'S' shape, dropping down and then immediately curving back up. A P-trap forms a 'P' shape, curving horizontally after the initial drop. P-traps are generally preferred in modern plumbing as S-traps can sometimes siphon away their water seal, allowing gases to escape.

How much does a plumber charge to unblock a sink?

As a rough guide for 2026, a professional plumber typically charges between £80 and £150 for a standard call-out to clear a blocked sink, depending on the severity of the blockage and your location in the UK. Emergency call-outs outside of normal working hours can range from £150 to £250. Always agree on the call-out fee upfront.

Need a plumber now? Tell us your emergency and FixDelivered will find and confirm an available local plumber near you, usually within the hour.

Written by the FixDelivered Team. Reviewed by Rupert Lowe, Editor. Last updated 2026-07-05.