278 High

Worcester Bosch 278 Fault Code

The Worcester Bosch 278 fault code means: your boiler has detected an issue with one of its internal sensors, meaning it cannot accurately check the temperature, so it has safely shut itself down to prevent any damage.. It appears on 5 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: F0 Sensor test failed
Typical repair cost £150-250 (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 278 fault code

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

Source

Worcester Bosch 278 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