235 High

Worcester Bosch 235 Fault Code

The Worcester Bosch 235 fault code means: your boiler's internal computer parts are having trouble communicating because they don't recognise each other's software versions.. It appears on 10 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: Conflicting versions of boiler electr. and boiler identification

What causes the Worcester Bosch 235 fault?

This fault occurs when the boiler's main control board and its dedicated memory chip are running different, incompatible versions of software. It usually happens after a component has been replaced or if a power surge has corrupted the data that allows these parts to talk to each other. Without perfect synchronization between these two electronic brains, the boiler cannot safely verify its own model identity and will stop working.

Typical repair cost £120-£450 (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 235 fault code

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

Source

Worcester Bosch 235 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 7 July 2026