BoilerFaultCodesWorcester Bosch F0278 Fault Code
The Worcester Bosch F0278 fault code means: your boiler has stopped working because its internal computer has detected a problem with the sensors that monitor its performance.. It appears on 1 Worcester Bosch model in our database.
Technical description: The sensor test has failed – cabling and plug sensors need checking
What causes the Worcester Bosch F0278 fault?
This fault happens when the boiler’s central brain performs a self-check and notices that the temperature sensors are not communicating correctly. It is usually caused by a loose connection in the internal wiring or a sensor that has reached the end of its life and is sending an impossible reading. Because the boiler cannot accurately track how hot the water is getting, it shuts down as a safety precaution.
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 F0278 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch F0278 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