BoilerFaultCodesWorcester Bosch 238 Fault Code
The Worcester Bosch 238 fault code means: your boiler's internal computer has encountered a critical error and can no longer communicate with the rest of the system.. It appears on 8 Worcester Bosch models in our database.
Technical description: Boiler electronics faulty
What causes the Worcester Bosch 238 fault?
This fault occurs when the boiler's main control board suffers a hardware failure and stops sending data to other internal components. It is often caused by a sudden electrical surge or an internal short circuit that has damaged the delicate microchips on the circuit board. Without these clear signals, the boiler cannot safely coordinate the ignition and heating process.
This fault is more common following summer storms, as power surges from lightning strikes or grid fluctuations can damage the boiler's sensitive electronic circuits.
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 238 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Worcester Bosch 238 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