4-F1 High

Worcester Bosch 4-F1 Fault Code

Also written as 4F1 — same fault.

The Worcester Bosch 4-F1 fault code means: your boiler has experienced a memory or software error and needs to be restarted to restore its original settings.. 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: Reset device to basic setting.
Typical repair cost £0-120 (including labour)

DIY fix possible

Locate the 'Reset' button on the boiler control panel.Press and hold the Reset button for 3 to 5 seconds.Wait for the boiler to complete its restart sequence and check if the display returns to normal.

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Worcester Bosch models that show the 4-F1 fault code

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

Source

Worcester Bosch 4-F1 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