375 Medium

Worcester Bosch 375 Fault Code

The Worcester Bosch 375 fault code means: your boiler has detected an electrical fault with a sensor that monitors the incoming water temperature, which may cause your hot water system to stop working correctly.. It appears on 4 Worcester Bosch models in our database.

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description: E4 Preheat sensor on DHW inlet Short Circuit
Typical repair cost £120-220 (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 375 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Worcester Bosch 375 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