Worcester Greenstar 25Si 30Si Boiler Expansion Vessel Connector 87161133040

Product Overview

The Worcester Bosch Greenstar Expansion Vessel Connector (Part Number: 87161133040) is a replacement hydraulic connection component designed for selected Worcester Bosch heating systems.

The connector forms part of the boiler's expansion vessel connection arrangement, providing a connection between the expansion vessel and the sealed central heating circuit.

The expansion vessel accommodates changes in heating water volume as the system temperature increases. A correctly fitted connector helps maintain the integrity of the hydraulic connection and supports the expansion vessel's pressure management function.

ℹ️ Product Condition Options:

This part may be available in New or Refurbished condition. Please select your desired option from the dropdown menu above. Refurbished components should be professionally inspected for damage, wear and leakage before installation.

Technical Insight & Common Failure Symptoms

The expansion vessel connector is a hydraulic fitting that forms part of the boiler's sealed heating circuit.

It provides a connection to the expansion vessel, allowing the vessel to accommodate changes in water volume during heating operation.

Damage, deterioration or leakage affecting the connector may compromise the integrity of the hydraulic connection and contribute to heating system pressure loss.

Possible signs that the expansion vessel connector or associated components require inspection include:

• Water leakage around the expansion vessel connection.

• Visible corrosion or deterioration of the connector.

• Cracks, deformation or physical damage to the fitting.

• Damaged or worn connection surfaces.

• Loose or insecure hydraulic connections.

• Heating system pressure loss associated with leakage.

• Damage identified during boiler servicing.

These symptoms do not necessarily confirm a faulty expansion vessel connector, as similar problems may result from damaged seals, expansion vessel faults or other hydraulic connections. Correct professional diagnosis should be carried out before replacement.

Compatibility

This part (MPN: 87161133040) is associated with selected Worcester Bosch Greenstar 25Si and 30Si boiler systems.

The connector is specified for relevant appliance versions manufactured after FD787.

Please verify the exact boiler model, GC number, FD production code, part number and connector specifications against the manufacturer's technical documentation before ordering to ensure correct fitment.

Safety Advice

Boiler expansion vessel connectors and associated pressurised hydraulic components should only be inspected, removed or installed by a suitably qualified and competent heating engineer.

Always isolate the appliance and allow the heating system to cool before carrying out any work. The heating circuit must be safely isolated and depressurised before removing the connector. Follow the manufacturer's servicing instructions and complete all required pressure, leakage and operational safety checks before returning the boiler to service.