Worcester Bosch Adaptor Return Pipe 87186810570

The Worcester Bosch 87186810570 is an adaptor return pipe used on Greenstar Compact and Si Compact appliances. It makes the connection between the heating circuit return pipework and the appliance's hydraulic assembly, providing the correct thread and seating depth for a sound joint. As a serviceable component it can be renewed on its own when the pipe end or the union is damaged.

• Water weeping or dripping from the return connection, often visible as staining or crusting around the union.
• Corrosion, scale or pitting on the adaptor body or its threaded end.
• A joint that will not seal cleanly after being broken and re-made.
• Discolouration or damp patches on the pipework immediately below the connection.
• Restricted flow through the return circuit where the bore has become blocked or distorted.

• Check the appliance model and GC number against the compatibility list before ordering, as the same part number is used across several Greenstar variants.
• The alternative number 1030957 may appear in place of 87186810570 on some documentation or stock records.
• Inspect the mating seal or washer at the same time and renew it if it is compressed or perished.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.