6 ways to unblock a kitchen sink

The kitchen is the hub of the home. You are likely to spend a lot of time preparing food, eating food and making your four or five cups of tea and coffee a day. So, if your kitchen sink is blocked, not only will there be a backup of water but an awful smell. 

In this post, we will tell you how to unblock your kitchen sink, and if all else fails, get in touch with our emergency drainage specialists.

kitchen sink washing

Is your sink blocked?

The first thing you should consider is if your kitchen sink is blocked. 

As mentioned above, the tell-tale signs are a bad smell you are not able to identify anywhere else in your kitchen, or the water is not draining away.

To make sure that it is not a problem for the whole house, you need to:

  • Flush a toilet: if the water level rises and does not return to a level just below where it narrows you may have an issue with your household drainage. 
  • Have a shower: if your bath or shower water does not drain quickly, that is another sign.
  • Find the closest outside drain to the house: it is likely that an outside drain next to your house is still on the same system, if there is water up to the grate there could be a bigger issue.

If you think it is not just the kitchen sink, run a CCTV drain survey and get the problem identified, then fixed quickly. A household drainage problem will only cause more catastrophic problems later.

Performing all three of these tasks will ensure that it is not a coincidence that your kitchen sink and your shower are blocked.

What causes a clogged kitchen sink?

The most common cause of a clogged kitchen sink is fat. As many times as we say it, pouring fat down your kitchen sink is bad for your drainage. 

Hot fat is liquid, however when it cools it solidifies. When poured down your sink it quickly cools and it can even mix with other chemicals and items to create a fatberg

Other causes of a blocked kitchen sink include:

  • Food: small pieces of food can flow, or be pushed, down the sink
  • Hair: pet owners may wash their animals in the kitchen sink, or dye their hair
  • Paper: people who clean their recycling may have paper flow down the sink

It may be a combination of the four, mixed together with soap to cause a blockage. However, more often than not you will be able to unblock your kitchen sink yourself.

6 ways to unblock your kitchen sink

Unblocking any sink yourself is usually possible without professional tools, or dismantling your pipes. Here is how you do it!

Boiling water

The first thing to always try before anything else is to boil your kettle and pour it slowly down the sink drain.

This will melt any fat that could be causing the issue, it will run through the pipes and dislodge any food caught by the fat. 

boiling kettle

Boiling water and salt

If boiling water on its own does not work, the next attempt should be with an additional ingredient, salt. Remove any excess water then pour half a cup of salt down the drain. Next, boil a kettle and pour the boiling water down the sink, leave it for a few minutes and see if that does the trick!

Baking soda and vinegar

These two household staples are perfect for unblocking your kitchen sink. Mixed together they cause a chemical reaction that can dislodge many stubborn blocks. 

Follow this five-step process: 

  1. Remove as much excess water as possible. 
  2. Then take one cup of baking soda and put that down your sink. 
  3. Next, get a different, but same-sized cup and fill it with vinegar and put that down the drain. 
  4. Plug the drain and this should cause the two to expand, pushing any blockage down. 
  5. Finally, boil your kettle, unplug the sink and pour boiling water down the drain.

Baking soda and salt

Baking soda and salt are another pair of household staples that react together to unblock sinks. These are two dry ingredients so you will need to wash the drain through at the end.

The four-step process with baking soda and salt:

  1. Mix together one cup of baking soda and one cup of salt. 
  2. Remove any excess water from the sink. 
  3. Pour the mixture into the drain and allow it to sit for a few hours, allowing the chemical reaction to take place. 
  4. Finally, rinse the drain with hot or warm water. 


If chemical reactions have not worked, it is time for a bit of force with a plunger. Well known for their ability to unblock toilets, they are great for unblocking sink drains as well. Plungers are also good for sinks that have a lot of standing water. 

When ready for the attempt, stand on a sturdy stool or chair for a bit of leverage and pump the plunger until the water starts to drain away.

plunger sink

Pipe snake

No luck with the brute force or a plunger? It is time for the pipe snake. They are relatively cheap at most hardware stores and are a bit more subtle than the plunger. 

Simply feed the snake down the drain until you feel resistance, and move it up and down to dislodge the block. Then run the warm tap until you are confident that the clog has been removed.

Watch this video for more help:

Maintain your Kitchen Sink Drainage

As with many things, prevention is better than the cure. Avoid pouring hot fat down your kitchen sink and try to remove any food items that may slip down. 

For very healthy kitchen drainage, you can use any of the above methods every three months. This will remove any unwanted issues that could transform into major drainage problems.

Contact the experts

If all else fails contact our drainage experts on 0800 043 4860. We service the whole of London and Hertfordshire, dealing with your drainage issue within one hour.