Due to the unprecedented situation with COVID-19 we have had to increase our minimum amount for free delivery to £100 exc VAT. There may also be some products you are unable to order/with longer delivery times. Find out more here


Product was successfully added to your basket.

Star Star Star Star Star

How To Bleed A Radiator

How to bleed a radiator

Do you have any radiators in your home which only heat up at the bottom and stay cold at the top? In most instances this can easily be resolved by bleeding the radiator and is simply due to trapped air inside of the heating system. How does air get inside of the heating system you ask? This can often happen as a result of adding extra water to the heating system during general maintenance or due to the action the pump makes, which can also create a small amount of air. Bleeding your radiators is simple and only takes a few minutes to do, take a look below at our step by step by step guide to bleeding your radiators.

What you will need:

Evaluate the Radiator

Firstly you need to identify which radiators in your heating system need to be bled. The best way to do this is by switching on your heating system and ensuring the radiators are all switched on. Once your heating system has warmed through, check the temperature of each radiator noting the ones which are cold or cooler at the top (take care when doing this as radiators can get very hot).   

Bleeding the Radiator

Once you have evaluated which boilers need attention, switch off the heating supply and cover the immediate floor with an old towel to protect your carpet and flooring.

Using a radiator key put the square part of the key in to the radiator valve which can be found at the top of the radiator on either of the sides. Slowly turn the key anticlockwise to help release the trapped air – if there is any air in the system you will hear it passing through the valve as a slight hissing noise. While doing this step it is best to use a small cloth or bowl to catch any drips of water which may come out of the radiator.

Continue to turn the key anti clockwise until there is no more air escaping from the valve. Once all of the air has been removed there will be large amount of fluid released from the valve, therefor it is important to close the valve quickly once the air has been removed.

Checking the Boiler Pressure

Once you have successfully bled each radiator the boiler pressure needs to be checked to ensure that the central system has not been affected by the removal of air. To do this view your boiler to see what the boiler pressure is according to the boiler gauge or computer display.

If the pressure is under the recommended level (this is often outlined on the gauge or can be found in the boiler manual) then you can try turning on a tap as this often resolves the problem.

If this does not fix the problem you may need to re-pressurise the boiler (for this task it is best to refer to your boiler information manual).

Hopefully this process will see your central heating system working efficiently and certainly save you money heading your home during the winter months. If your heating system is still not working correctly, you may have a system problem that needs to be looked at by a qualified heating engineer or plumber.

Here at Direct Heating Supplies we offer a great range of radiators, towel rails and accessories to suite all of your D.I.Y needs so you can personalise each room to your individual tastes. Click here to view our full range of products and to find out more about the types of radiators we offer.