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What do you do when your kitchen sink won't drain?

What do you do when your kitchen sink won't drain?

The sight of grey dishwater sitting stagnant in the sink is one that many homeowners dread. If you’re facing this unpleasant sight, read on to learn how you can tackle this problem.

What causes a sink blockage?


There are three very common reasons why your kitchen sink won’t drain.

  • Oil and grease
  • Soap scum
  • Food debris

And, more often, it’s a mix of all three that causes the problem. Grease and oil are the most common culprits. Pouring hot grease down the drain is a big no-no. When the grease cools, it solidifies and this can easily get caught on the pipes and start to collect other pieces of debris. Before long, your pipes become completely blocked.

Soap is another common culprit. You might be wondering how something that is supposed to keep your kitchen clean could cause a blockage. When soap comes into contact with minerals in your tap water, it leaves behind soap scum which can build up in your pipes and allow food debris and other things to stick in your pipes. 

Slow draining sink


The first step to diagnosing a blocked sink is to determine if the flow has slowed down or stopped entirely. If the water is moving slowly, this suggests a build-up of debris in your pipes. This can be fixed using one of the following methods:

  • Boiling water is a simple and inexpensive way to unclog your sink drain. If the blockage is caused by oil or grease, the heat will help to ease it away. Boil a full kettle and slowly pour all the water down the drain, being careful not to splash yourself. 
  • Baking soda and vinegar are also essential items to have on hand in the event of a sink blockage. Allow the sink to drain as much as possible and then pour baking soda down the drain (bicarbonate of soda, not baking powder). Follow this with a cup of vinegar. The mixture will fizz up. Leave it to sit for at least 30 minutes and then flush the pipe with hot water from the kettle. This will clean out any debris and also help to neutralise bad smells.
  • Chemical plughole unblockers are available in many supermarkets and hardware shops. Follow the instructions on the packaging to unblock your plughole. 

Completely blocked sink


If the water is not moving at all, you may need to reach for the plunger to get the water flowing again. Plungers need a sink full of water to create a seal. Position the plunger over the plughole and push straight down a few times. Remove the plunger and see if the water has started to drain. Do this a few times to try to push the blockage down the drain.

If you cannot unblock your kitchen sink with a plunger, try using a plumber’s snake. There are expensive versions of these or you can buy a cheap plastic one. This flexible piece of plastic has small barbs which are designed to latch on to blockages and allow you to pull them back up the drain.

Insert the plumber’s snake into the plughole and slowly move it down the drain. It should be able to work its way around the U bend easily. When you reach the blockage, try to dislodge it using the snake. It will help to see if it is effective if you leave water in the sink. 

If you can’t dislodge the blockage, try pulling it back up by getting it caught into the barbs of the plumber’s snake. This is particularly effective if you have hair blocking your pipes.

After removing the blockage, try one of the methods above to clear any remaining debris from the pipes. 

How to prevent sink blockages

When it comes to sink blockages, it’s easier to prevent them than it is to fix them. A few simple steps could help you to avoid blockages in the future.

  • Never pour fat or grease down the drain. Allow it to cool and then pour it into a bottle to dispose of safely. If you are washing a greasy pan, always wash it with plenty of hot running water and leave the water running for a minute after you have finished washing the grease away. 
  • Use a plughole screen to catch food debris before it can cause problems for your drain. As much as it’s easier to force food down the plughole instead of throwing it in the bin, this could cause a lot of problems down the line, not to mention that you’re more likely to have a smelly drain as the food decomposes.
  • Regularly flush your kitchen plughole with hot water to help remove any small deposits before they become problematic.

If you’re still faced with a blocked sink that isn’t helped by any of the steps above, it might be time to call in the experts. With home and boiler care from YourRepair, you’ll be covered for blocked drains and so much more. Get in touch today to find out more.

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