How to bleed a radiator

September means the return of autumn nights and colder weather, so before summer ends, tick a job off your to-do list and ensure your central heating system is prepared for the winter months by bleeding your radiators. 

If your radiators take a long time to heat up or have cold spots, it may be time to give them some TLC. This simple step will ensure your house remains toasty warm and save you precious pennies on your energy bills. 

How do I know when my radiator needs bleeding?

As noted, you should bleed your radiators when they no longer heat up properly, have cold spots, or make a rattling/clunking noise. 

These symptoms result from trapped air stopping the warm water circulating your system, meaning your radiator will heat at the bottom but not the top. This, in turn, means your energy bills are higher as your system works harder to heat the room to your desired temperature.

Tools for the job

  • A radiator key — available in all DIY shops.
  • An old cloth/bowl.

How to bleed your radiator in five simple steps.

  • Turn off your central heating; this is essential to avoid hot water spraying out of your radiators and causing any burns or accidents. 
  • Use your radiator key to turn the valve at the top. The square peg should slot easily into the groove, and you can begin to turn in an anti-clockwise motion. Do this slowly, as the trapped air will start to hiss out. Pop an old cloth/bowl underneath the valve to catch any water that may escape. 
  • Retighten the valve once the hissing has ceased to avoid too much water leaving your radiators. 
  • Turn your central heating system back on for a few minutes; check if your radiators are getting warm at the top.
  • Head to your boiler and check the pressure gauge is in the green area, as bleeding your radiators can cause a temporary drop. If your pressure is low, use the filling loop to top it up. 

There you have it! A straightforward guide to ensuring your central heating system is running efficiently. For more tips on securing your home in time for winter, read our blog on choosing the right boiler for your property. Should you have any questions, don’t hesitate to contact us.

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