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If you find that your radiator is hot and cold in places, it is most likely that your radiator needs bleeding. This is a simple first-step solution that can be done before calling out an engineer.


Trapped air in the radiator can restrict the circulation of hot water, which means less heat is emitted and it will take longer to heat your home. If you do not bleed your radiators you may find you are using more energy to heat your home.


Follow these quick and easy steps to bleed your radiators and save costs on your energy bills.


  1. Turn off your heating and make sure the radiators are cool.
  2. You will need a radiator key (can be purchased from most DIY stores) and a cloth. On one end of the radiator, there will be a radiator valve. Using the radiator key, put the key in the valve, turn slowly and anti-clockwise, which will open the radiator valve.
  3. Once you have turned the key, you will begin to hear a hissing sound, which is the air escaping. At some point, the hissing noise will stop and water will start to leak out of the valve. Make sure you hold the cloth underneath the radiator key at this point to absorb the water.
  4. Once water starts to leak from the valve, turn the key back (clockwise) to resecure the valve and tighten to a close.
  5. Now your radiator has been bled, check the pressure on your boiler. If the pressure is normal you can turn your heating back on and check the radiator. You may find the pressure has dropped, in which case you will need repressurise the boiler. Please refer to our guide How to repressurise a boiler if required.


Clockwork recommends you do a check on the radiators in your home on a quarterly basis. If you have followed the above steps and find that your radiators are still not producing adequate heating, we would advise calling an engineer for a further investigation. Contact Us!


This is the radiator valve and will be found on one of the sides.

This is the radiator valve and will be found on one of the sides.

Using a radiator key, turn in an anti-clockwise position.

Hold a cloth underneath the valve for when all the air is released and the water reaches the valve. At this point turn the key in the valve to a close.

Talk to us for more information

If you’d like to discuss our service options and packages or need advice regarding maintenance issues, please give us a call on 02920 602444 or:

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