Worcester Bosch Pipe Expansion Vessel 8737604650

The pipe (expansion vessel) is a Worcester Bosch component, part number 8737604650. It is the pipe connection that links the expansion vessel to the heating circuit on Worcester Bosch Greenstar combi appliances. It carries system water between the vessel and the boiler's hydraulic assembly.

• Water weeping or staining at the expansion vessel pipe connection
• Corrosion or pitting on the pipe surface or at the joint
• Repeated loss of system pressure traced to the pipe run
• Scale or debris build-up restricting flow through the pipe

• Confirm the appliance model and GC number against the Fits list above
• Identify the pipe run and connection point on the expansion vessel before removal
• Check the expansion vessel itself for charge and diaphragm condition while access is available
• Depressurise and drain the heating circuit before removing the pipe