What is an air vent / bleed valve?
An air vent (also called a bleed valve) is a small valve, which enables air* that has accumulated at the top of a radiator to be let out or bled from the radiator using a special air vent key. All our central heating radiators will have an air vent, which will be sent out with the radiator, and should be fitted as part of the installation. Bleed/Vent keys are not included as standard, but can be purchased from a plumbers merchants or a home improvement store – with most of our bleed vents a screwdriver can be used. * on first filling the system it is air that is vented, the periodic venting of systems is actually releasing hydrogen which is the by product of rusting in the system, if regular bleeding is required this is a strong indication that the system requires draining and refilling incorporating a corrosion inhibitor.