Worcester Bosch 225 Fault Code
The Worcester Bosch 225 fault code means: your boiler has detected that the water temperature is behaving unexpectedly compared to its safety settings, so it has shut down to prevent potential overheating.. It appears on 4 Worcester Bosch models in our database.
Technical description: Difference between flow and safety exceeding limit (bi-sensor only)
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 225 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 225 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
- Worcester Bosch 24/28/35 CDi MkII manual (PDF)
- Worcester Bosch Greenstar 12i System manual (PDF)
- Worcester Bosch Greenstar 28CDi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026