231 Medium

Worcester Bosch 231 Fault Code

The Worcester Bosch 231 fault code means: your boiler has detected a brief loss of electricity or a unstable power supply, causing it to shut down for protection.. 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: FD Mains power error - electrical power interruption
Typical repair cost £100-200 (including labour)

DIY fix possible

Check that the boiler isolation switch and your property's main fuse box (consumer unit) are fully switched on.Unplug the boiler from the wall socket (if applicable) for 30 seconds and plug it back in to perform a soft reset.If the code persists, check for any loose power connections or recent local power cuts in your area.

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Worcester Bosch models that show the 231 fault code

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

Source

Worcester Bosch 231 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