259 High

Worcester Bosch 259 Fault Code

The Worcester Bosch 259 fault code means: your boiler has detected an internal communication error between its internal components, causing it to shut down for safety until the electronic system can be reset.. It appears on 7 Worcester Bosch models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: FO AD reference error
Typical repair cost £150-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Worcester Bosch models that show the 259 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch 259 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026