As temperatures drop across the UK, British Gas is urging households to tackle a common – and often overlooked – cause of poor home heating: trapped air inside radiators.
When air becomes stuck at the top of a radiator, it prevents hot water from circulating properly. The result? Patchy heat, cold spots, and a boiler that has to work harder than necessary. Not only does this affect comfort, it can push energy bills higher and strain heating systems.
The £1 fix that could make a big difference
The energy provider says one simple maintenance task can restore warmth and efficiency: bleeding your radiators. The process releases trapped air, allowing hot water to flow freely again.
What you’ll need is a radiator bleed key — widely available at DIY stores for around £1.
How to bleed a radiator:
Switch off your heating and allow radiators to cool.
Place a towel or small container beneath the bleed valve.
Using a radiator key, gently turn the valve until you hear a hiss of escaping air.
When a steady stream of water appears, tighten the valve.
Turn your heating back on and check that the radiator heats evenly from top to bottom.
While some household tools can occasionally substitute for a radiator key, specialists recommend using the proper tool for better fit, ease of use and, in many cases, lifetime guarantees.
Savings and efficiency gains
The benefits of bleeding radiators go beyond comfort. According to Ideal Home, a well-maintained heating system can run up to 15% more efficiently, potentially saving households as much as £45 per radiator over the winter months.
Regular bleeding also reduces the workload on your boiler, helping the system run more smoothly and lowering its environmental impact.
Safety remains essential
Anyone planning to bleed their radiators should take basic precautions: ensure radiators have cooled fully and check boiler pressure afterwards. Failing to monitor pressure can cause further heating problems and undermine the benefits of the maintenance. Photo by British Gas, Cardiff by Jaggery, Wikimedia commons.