What if the top section of my radiator is cold?

This probably means there’s air in the system and the radiator needs ‘bleeding’.

What if the bottom section of my radiator is cold or luke-warm?

This means rust and sludge are obstructing the bottom part of the radiator. To clean your radiator you will need to remove it.

What if only the upstairs radiators are cold?

This may mean that the feed and expansion cistern in your loft has run dry, often caused by a jammed or obstructed ball valve.

Radiator Tips

To bleed your radiator:

  • Turn off the heat
  •  Find the bleed valve, this is usually on one side near the top
  •  Place a cloth underneath the bleed valve
  • Use a radiator key to gently release the valve and listen for the hiss of escaping air
  • Tighten the valve as soon as water begins to flow, and use the cloth to clean up – be careful as the water can be scalding hot
  • Switch the heat back on

To clean your radiator you will need to remove it:

  • Turn off the heat
  • Protect the carpet or floor with cloths or plastic sheeting and fetch a spanner or pliers, a wrench and a few bowls or buckets to catch the water
  • Close the valves at each end of the radiator. You will need to remove the plastic shield from the ‘lockshield valve’ and close it with the spanner or pliers
  • Open the bleed valve, at the side near the top of the radiator, to allow the water to escape. If water keeps running then the other valves are not closed properly
  • Use the bowls/buckets to catch any water and undo the nuts that hold the radiator to the valves on each end. Do this slowly to ensure you can catch all the water
  • Get someone to help lift a heavy radiator from the brackets
  • Drain any remaining water into the bowls/buckets
  • Keep the radiator upright and carry it outside
  • Stand the radiator on end, flush out the sludge with a hosepipe and clean it thoroughly