Trapped air can be a common issue in systems and it can lead to reduced efficiency and uneven temperature output if not treated properly. When a build-up of air accumulates in the system, the float inside the air vent will rise to release the air pocket automatically to allow water to come in and top up the system accordingly.
Installing this type of air vent helps to reduce and often eliminate the need for manual bleeding of the system which can take a long time as bleed points are often located in awkward areas.
Automatic air vents must be installed vertically as their operation is based on vertical movement of the float. This ½" version incorporates a check valve so it can be taken off easily for either replacement or servicing without having to drain the cylinder.