The Worcester Bosch 87161425020 FSN expansion vessel (8 L, Ø 389 mm) is a genuine OEM pressure-management component designed to stabilise central heating system pressure in compatible Worcester Bosch FSN, 24i, 28i and 30i boiler installations. As water in a closed loop heats up and expands, the internal diaphragm of this expansion vessel absorbs the increase in volume, helping prevent excessive pressure rise that can lead to system faults, safety valve discharge or stress on pipework and components. Engineered to original equipment standards, it delivers reliable performance, maintaining the safe and efficient operation of smaller domestic boiler systems.

This 8-litre expansion vessel with a 389 mm diameter is compatible with Worcester Bosch FSN, 24i, 28i and 30i boilers that specify part number 87161425020 for pressure stabilisation. Because expansion vessel sizing, connection fittings and system configurations vary by model, output and installation type, it’s recommended to confirm suitability using your boiler’s exact model number and GC number before ordering.

Key features of the Worcester Bosch 87161425020 FSN expansion vessel (8 L, Ø 389 mm) include its genuine Worcester Bosch manufacture for assured quality and compatibility, 8 litre capacity with 389 mm diameter suited to compact boiler systems, internal diaphragm design to manage thermal expansion and stabilise system pressure, robust pressure-rated body designed for routine heating system demands, and dependable performance when installed by a qualified heating engineer to help maintain safe, efficient boiler operation.