238 High

Worcester 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 10 Worcester Bosch models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

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.

Typical repair cost £350-£650 (including labour)

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 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 7 July 2026