How To Bleed A Radiator Within A Central Heating System

Posted : Tuesday 22nd July 2014

It is common for air to become trapped in a central heating system which causes an air lock, resulting in little or no heating being produced from your radiators. The main causes of air becoming trapped is either the wrong sequence when refilling a system and/or air being drawn in at some point (usually from a small leak or a tiny hole within the central heating system).

How to bleed your radiators

To remove the air lock, you will need to bleed the radiators, it is very important that you do this in the correct order. See the guide below:

  • Switch off the boiler and isolate the electrics.
  • When turning off the valves, make a note of the number of turns required.
  • Turn off all the upstairs radiators and work on the downstairs ones first.
  • Bleed valve with the return valve closed and the flow valve open.
  • Open the bleed valve at the top of the radiator.

As this air is released, water will replace it via the flow pipe. Once air has been cleared from the first radiator, close both radiator valves as well as the bleed valve. Move on to the second radiator on the circuit and repeat the process.

Once all downstairs radiators have been bled, move on to the upstairs radiators and bleed those one at a time as before. By the time you have worked on all the radiators you will have eliminated all air from them.

This article was provided by the local London Plumbers Tems-Gas. They cover all aspects of plumbing, heating and boiler repairs to both residents and businesses of London. All their plumbers are fully qualified, experienced and registered. Whether you require a plumber in Norwood or an heating engineer in West Wickham, Tems Gas can help. Please visit: for more information.

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