Why bleed a radiator?

Air trapped in your radiators prevents hot water from filling the whole panel, leaving cold spots and reducing heating efficiency.

What you'll need

• A radiator bleed key (a few pounds from any DIY shop)
• A small bowl or cloth

Steps

1. Turn off your heating and let radiators cool.
2. Place a bowl under the bleed valve (usually at the top corner).
3. Insert the key and turn slowly anticlockwise — you'll hear a hiss as air escapes.
4. Close the valve as soon as water starts to drip.
5. Check your boiler pressure — bleeding can drop it, top up if needed.

Top tip

Bleed all your radiators at once, starting with the one furthest from the boiler.