BoilerFaultCodesWorcester Bosch 363 Fault Code
The Worcester Bosch 363 fault code means: your boiler has encountered an internal communication error between its main electronic control boards, meaning it cannot currently function or heat your home.. It appears on 7 Worcester Bosch models in our database.
Technical description: System fault boiler electronics / basic controller
What causes the Worcester Bosch 363 fault?
This fault occurs when the boiler's two main 'brains'—the primary control board and the display board—stop talking to each other. It is usually caused by a loose internal connection, a glitch in the software, or a component failure on one of the electronic circuit boards. Think of it like a computer crashing because two internal parts can no longer share information.
DIY fix possible
Locate the power switch or fused spur for the boilerTurn the power off, wait for 30 seconds, and turn it back onPress the 'Reset' button on the boiler display once it restarts
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A cover plan would handle faults like 363: no call-out fees, no surprise bills.
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Worcester Bosch models that show the 363 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 363 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