Planning & preparation
- A blocked sink is a common problem that tends to be caused by a build-up of everyday debris and food getting caught in the pipe below the sink
- A blockage can usually be fixed with a plunger, a product such as a blaster cup, plumber’s snake or a chemical drain cleaner. However, if a larger object has become wedged in the pipe then you’ll need to remove the blockage manually
- Several methods for unblocking a sink are shown in this guide, but if your problem persists then call in a professional
Do it right
- Dispose of waste from the U-bend or strainer into a bin rather than flushing back down the sink
- When plunging or using a blaster cup, always block the overflow with a wet cloth to ensure an airtight seal
- If you’re using a chemical drain cleaner, try and choose one that is eco-friendly and biodegradable, and always follow the manufacturer’s directions for use
- Turn off the water supply before carrying out any plumbing work
- Wear gloves if using a chemical drain cleaner and always follow the safety recommendations on the packaging of any product used
- Carefully disposing of cooking oil and ground coffee will help keep your sinks clear. Fitting a drain grate or screen will also help to keep things flowing
- Regular maintenance includes flushing the sink with hot water, occasionally using a heaped teaspoon of baking soda sprinkled into the plughole, or a cup of white vinegar poured down the plug hole and left for around 30 minutes
- Use of an eco-friendly drain liquid can help prevent blockages, but always check all manufacturer's instructions
- Store manufacturer’s instructions for your sink and tap somewhere safe, as this information could help you to solve the problem as quickly as possible
How to remove small blockages
Place a plunger or blaster cup over the plug hole. Then, block the overflow with a wet cloth to create an airtight seal.
Gently pump the plunger or blaster cup up and down whilst keeping the overflow firmly covered. This should be enough to dislodge small blockages.
If this fails to clear the blockage, then try using a liquid drain cleaner. Be sure to wear protective gloves while using this product.
Pour the liquid down the plughole, as per manufacturer's instructions, and a fizzing reaction will occur as the debris is broken down.
Repeat a few times and then rinse through with warm water.
If the blockage persists, try using a plumber’s snake. To use, carefully push the snake down the drain whilst twisting to help it get around the U-bend.
Once you reach the obstruction, pull, twist and push the plumbers snake until the blockage is removed. Then rinse through with cold water.
How to remove large blockages
If none of these methods have worked it’s time to deal with the plumbing directly. Start by identifying the first bend in the pipe underneath the sink; this is a U-bend called the ‘trap’.
Turn the water supply off by turning the stopcock clockwise.
Place a bucket or watertight container underneath the trap to catch any water that spills out.
Unscrew the two compression fittings that hold the trap in place. You may need to use a wrench if the compression fittings are especially tight.
Carefully remove the trap and empty the water into the bucket or container below.
Take a look inside the trap and remove any debris that has built up using a piece of stiff wire. Throw the waste from the pipe in the bin to avoid further problems.
Once the trap has been unblocked, secure it back into position underneath the sink.
Turn the water supply back on by turning the stopcock anti-clockwise.