Worcester Bosch Automatic Air Vent Greenstar RD Series 87185050390

The Worcester Bosch automatic air vent is a pressure safety component fitted inside the central heating unit. It uses buoyancy to release air that accumulates in the system: as water circulates and the appliance heats and cools, a float inside the vent rises or falls with the water level. When the system is full of water the float is pushed to the top and the vent stays closed; when the water level drops, the float falls and the trapped air is discharged.

This is the vent used across the Worcester Bosch Greenstar and RD series appliance families.

• Radiators that are cold at the top and need bleeding repeatedly
• Air noise, gurgling or kettling from the boiler or pipework
• Water weeping or dripping from the vent body
• System pressure that falls and needs regular topping up
• The vent no longer discharging air when the system is bled

• Check the GC number and serial plate on the appliance against the compatibility list to confirm the correct variant.
• Confirm the model is listed for this part number before ordering, as several Greenstar and RD variants use different vent assemblies.
• Check whether a sealing washer or gasket is required at the same time, as the old seal is often disturbed when the vent is removed.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.