Commonly fails. No need to buy a complete valve just replace the O-ring and it will reseal.
5x Central Heating Bleed or Blank Cap Radiator Valve Replacement O-rings / Seals
10x White Radiator Bleed Valves 1/2" BSP 15mm - Manual Air Vent Plug Trade Pack
Goodility Brass Radiator Key for Bleeding Radiators, 5mm Radiator Bleed Key UK, Pack of 2 Solid Radiator Air Vent Keys for Optimizing Central Heating Systems
Event Decor Shop Solid Brass 5mm Universal Radiator Bleed Key – Heavy-Duty Valve Key for Air Venting and Bleeding UK Radiators, Ideal Plumbing Tool for Central Heating Systems - Pack of 1
2 Radiator Keys Set Bleed Valve Tool for Central Heating System Air Release +
5pcs 12 Inch Air Vent Radiator Bleed Valve for Central Heating Systems
