Watch our Video on How to Bleed a Radiator

You can follow the instructions below or watch how this is done by viewing our How to Bleed a Radiator video

This relates to customers with gas-fired back boilers and solid fuel boilers.

Before bleeding a radiator:

  • If the whole radiator is cold, check that the radiator control and lock shields are open.  If more than one radiator is cold, the whole system needs to be checked by a plumber
  • Turn off the heating system before bleeding
  • You need a special radiator key available from DIY stores.  You will also need an old rag or cloth and a bowl.

How to start

  • The bleed valve is a small square nut at the top end of the radiator
  • Place the key over the valve and hold a cloth around it to soak up any water
  • Gently turn the key anti clockwise until you hear a hiss – this is the air being released
  • DO NOT unscrew the valve completely
  • When water starts to come through, turn the key back clockwise to shut the valve off.
  • Once the radiator has been bled, check the pressure gauge on your boiler. If the pressure is low you will need to re-pressurise the boiler.