How to Unblock Sink: A UK Homeowner's Guide
That sinking feeling when water refuses to go down the drain is a common frustration. But before you call a plumber, there are simple, effective tricks you can try yourself. Most of the time, the culprit is a build-up of grease and food scraps, which are surprisingly easy to deal with.
Let's start with the basics. These are your first lines of defence and often get the job done without any fuss.
Boiling Water
The simplest solution is often the best. Pouring a full kettle of boiling water directly down the plughole can work wonders on greasy clogs common in kitchen sinks. The heat melts solidified grease, helping to wash it away. Just be careful not to splash yourself!
The Classic Baking Soda & Vinegar Trick
If hot water alone doesn’t shift it, it’s time for the classic duo: baking soda and white vinegar. This combination creates a fizzy reaction that can break down stubborn grime and food particles. It's a much gentler alternative to harsh chemical drain cleaners.
Using a Plunger
For more solid blockages, a good old-fashioned plunger is your best friend. A simple cup plunger creates powerful suction and pressure that can physically dislodge whatever is causing the blockage. It’s a bit of manual work, but it’s incredibly effective.
Quick DIY Sink Unblocking Methods
| Method | Best For | Instructions | Safety Note |
|---|---|---|---|
| Boiling Water | Grease, soap scum, and minor food build-up. | Boil a full kettle. Pour it slowly and directly down the drain. | Be cautious with PVC pipes as extreme heat can soften them. Avoid splashing. |
| Baking Soda & Vinegar | Mild clogs, food waste, and deodorising the drain. | Pour one cup of baking soda, followed by one cup of white vinegar. Cover the drain for 5-10 minutes, then flush with hot water. | The reaction creates fizzing; covering the drain contains the pressure. |
| Plunger | Solid obstructions like trapped food or hair. | Fill the sink with enough water to cover the plunger cup. Place the plunger over the drain, ensuring a good seal, and plunge vigorously. | If you have a double sink, block the second drain with a cloth to maintain pressure. |
These simple techniques can solve many sink blockages. Of course, plumbing issues can sometimes be more complex. If you're dealing with other problems, knowing how to approach them, such as troubleshooting and fixing a leaking kitchen faucet, can also save you time and hassle.
Understanding What’s Blocking Your Sink
Before you start, it’s worth figuring out what you’re up against. In the kitchen, the usual suspects are fats, oils, and grease (FOG). When these cool, they solidify inside your pipes, creating a sticky trap for food scraps. This is a huge problem, with over 70% of sewer blockages being preventable, costing UK water companies £90 million a year to clear.
Bathroom sinks are more likely to be blocked by a matted plug of hair, soap scum, and toothpaste. Knowing the likely cause helps you choose the right method. For more detail, see our guide on the four common causes of blocked drains.
Tackling Tougher Clogs with Manual Tools
If you’ve tried boiling water and the baking soda trick without success, it’s time to get more hands-on. Some blockages are too deep or compacted for simple solutions. This is where a plumber’s snake (drain auger) or cleaning the P-trap comes in.
The P-trap is the U-shaped pipe under your sink. Its curve stops sewer gases from coming up but also makes it the perfect spot for debris to collect and form a clog. Cleaning it out is a straightforward job that can fix even persistent drainage problems.
How to Clean the P-Trap
- Place a bucket directly underneath the P-trap to catch water and gunk.
- Use a wrench or pliers to loosen the two large plastic nuts (slip nuts) holding the U-bend in place.
- Pull the trap away and empty its contents into the bucket.
- Rinse and scrub the pipe to remove any residue.
- Reassemble everything, ensuring the nuts are tight to prevent leaks.
Of course, prevention is better than cure. A few small changes to your routine can keep your drains flowing freely. Scrape food scraps into the bin, use a sink strainer, and never pour cooking fats, oils, or grease down the drain. A recent UK survey revealed that a staggering 80% of blockages are avoidable, with FOG being the main culprit. You can learn more about the scale of the problem in this review from Unblocktober.
Pro Tip: Once a week, pour a full kettle of boiling water down the kitchen sink. This quick flush helps dissolve greasy build-up. If you're dealing with smells, we have advice on how to stop smells from drains.
Knowing When It's Time to Call a Plumber
While most blockages are a simple DIY fix, you need to know your limits. A stubborn clog can be a symptom of a bigger problem deeper in your pipes. Knowing when to call a plumber can save you from mess and expensive water damage.
If clogs keep coming back, or several drains in your house are slow at once, that’s a red flag. It often points to a serious blockage in your main drain line, which is beyond a DIY fix. A persistent foul smell you can’t shift is another tell-tale sign. In fact, surveys show that 53% of UK homes have had to call out a plumber for blocked drains. If you suspect a severe problem, it’s best to contact technical plumbing services who have the right tools.
If you’ve exhausted all the DIY options and that water still isn’t going anywhere, it’s time to call in an expert. A professional plumber has the specialist tools and experience to fix the problem safely and efficiently.
For advice on finding a reliable engineer, check out our guide on how to find a good plumber.
Your Blocked Sink Questions, Answered
Is It a Good Idea to Use Bleach to Unblock a Sink?
In short, no. Bleach is ineffective at breaking down grease and hair. More importantly, if it mixes with other chemicals in your drain, it can create toxic fumes. Stick to safer methods like boiling water or a plunger.
What’s Causing That Awful Smell From My Sink?
The odour is usually caused by old food, grease, and bacteria in your P-trap or pipes. A monthly cleanse with baking soda and vinegar can neutralise smells. If the pong persists, you might have a more serious issue with your plumbing vents.
How Often Should I Be Cleaning My Drains?
Prevention is key. For kitchen sinks, a weekly flush with boiling water stops grease from building up. For a deeper clean, use the baking soda and vinegar method once a month on all sinks in your home to stop small issues from becoming big headaches.
If you’ve tried all the tricks in the book and that clog just isn't shifting, it’s time to call in the experts. For a fast, reliable fix, book one of our expert plumbing engineers at Go Assist. Find out more and book your repair online today.
