HOW TO... BLEED A RADIATOR
It’s a good idea to bleed your home’s radiators ( to release trapped air) before starting to use the central heating again.
Radiators containing trapped air are hot at the bottom but cold further up, so they’re not giving off as much heat as they could. Bleeding them is easy – simply put a radiator key or small screwdriver (depending on the type of hole) into the bleed valve on the radiator and carefully open the valve to let out any air – you should hear the air escaping.
Close the valve when liquid starts coming out. This job can be messy, so protect the flooring underneath the bleed valve and have a cloth to hand.
Don’t bleed radiators when the heating is on, or when the heating is off but the radiators are still hot, and don’t leave a radiator unattended while you bleed it.