BoilerFaultCodesWorcester Bosch 2963 Fault Code
The Worcester Bosch 2963 fault code means: your boiler has detected that the sensors monitoring its internal temperature are giving incorrect readings or have failed, causing the system to shut down for safety.. It appears on 5 Worcester Bosch models in our database.
Technical description: The heat exchanger sensor or both supply and heat exchanger sensors are defect
What causes the Worcester Bosch 2963 fault?
This fault occurs when the boiler's control board receives conflicting or impossible temperature data from the internal sensors that monitor the main heat exchanger. This usually happens because a sensor has developed an internal electrical fault or the wiring connecting it to the main computer has become loose or corroded. To prevent the unit from overheating, the system shuts down immediately because it can no longer safely track how hot the water is getting.
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 2963 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 2963 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 Greenstar 1000 manual (PDF)
- Worcester Bosch Greenstar 2000 manual (PDF)
- Worcester Bosch Greenstar 27CDi manual (PDF)
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026