BoilerFaultCodesWorcester Bosch B2 Fault Code
The Worcester Bosch B2 fault code means: your boiler's main electronic brain has encountered an internal error and has stopped the system from running to prevent potential damage.. It appears on 7 Worcester Bosch models in our database.
Technical description: Control box fault
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Worcester Bosch models that show the B2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch B2 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 27 April 2026