Blue Light Flashing High

Worcester Bosch Blue Light Flashing Fault Code

Also written as BLUELIGHTFLASHING — same fault.

The Worcester Bosch Blue Light Flashing fault code means: your boiler has detected a general internal fault and has automatically stopped running to keep your system safe.. It appears on 1 Worcester Bosch model 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: A fault condition has occurred. To reset the boiler: Press the reset button for five seconds. When the reset is successful the reset button will no longer be illuminated and the blue light will stop flashing and remain constant.
Typical repair cost £100-250 (including labour)

DIY fix possible

Locate the reset button on the front control panel.Press and hold the reset button firmly for five seconds.Wait for the blue light to stop flashing and remain steadily illuminated.

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Worcester Bosch models that show the Blue Light Flashing fault code

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

Source

Worcester Bosch Blue Light Flashing 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