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With cold weather sweeping the nation, it’s vital that your central heating is working as efficiently as it can be.


Ensuring that your radiators are functioning properly by ‘bleeding’ them i.e. releasing air that is trapped inside, is the first step to improving the overall efficiency of your central heating system. This is a straightforward task for most people and should not require a plumber! Check out our handy article below for a step-by-step method.


how to bleed a radiator


Step one

To see which radiators require bleeding, turn your central heating on and give them enough time to fully heat up. It’s important to allow the pressure to build within each radiator, so that excess air is evacuated.

Step two

A simple method for seeing which radiators require bleeding is by gently touching each radiator with your hand. Be careful during this stage, as your radiators may be very hot. However, in some spots, they may feel lukewarm or even completely cold; this is a sign that there is air trapped inside and bleeding is required.

Step three

Once you have identified which radiators need bleeding, turn your central heating off. This decreases the risk of leaks, making the job a whole lot easier.

Focus on the valve on the top of the radiator and you should see a square section within this, which is what you need to turn using a radiator key, or an appropriate screw driver, you should use a towel to grip the radiator and to protect your hands. If you do not have a radiator key, you can find one in most DIY stores.


how to bleed a radiator


Step four

Turn the key or screw driver anti-clockwise and listen for the air/ gas escaping from the radiator. Once the air has stopped being released, water should leak out and this indicates that the air has been fully dispersed.

Step five

When the water starts to leak out, get ready to quickly tighten the valve back on. At this stage there may be some excess water that needs to be cleaned up.

Wait a couple of hours before turning your radiators back on and you will then be able to test the radiators to see if they have been successfully bled.

Step six

To test that the process has worked correctly, go back and follow steps one and two. If cooler patches still exist, it may be that there is air still trapped inside the radiator and you need to start again.

If your radiators feel the same temperature across the whole surface, congratulations you have successfully bled your radiator!

Having fully working radiators is essential for ensuring that your home is warm and dry, to lessen the risk of condensation. Discover our other articles on how to prevent condensation here:

Why does condensation occur in the winter?

How to deal with condensation, damp, and mould as a landlord

How to prevent condensation