BoilerFaultCodesWorcester Bosch 253 Fault Code
The Worcester Bosch 253 fault code means: your boiler's internal computer has encountered a software or hardware communication error, preventing it from starting up correctly.. It appears on 8 Worcester Bosch models in our database.
Technical description: System fault boiler electronics / basic controller
What causes the Worcester Bosch 253 fault?
This fault occurs when the boiler's internal computer chips fail to communicate or 'handshake' with each other during the start-up sequence. It is usually caused by a physical hardware failure on the main circuit board or a loose connection in the internal wiring. Essentially, the boiler's brain has encountered a critical error that prevents it from safely managing the heating process.
DIY fix possible
Press the 'Reset' button on the boiler control panel onceSwitch the main electrical power to the boiler off and back on again after 30 secondsCheck if the error clears and the boiler restarts its ignition sequence
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Gas Safe Register →Worcester Bosch models that show the 253 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 253 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