8/0/3 Medium

Worcester Bosch 8/0/3 Fault Code

Also written as 803 — same fault.

The Worcester Bosch 8/0/3 fault code means: your boiler has lost its internal clock settings, likely due to a recent power cut, and needs to be reset to allow it to operate correctly.. It appears on 1 Worcester Bosch model 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: Date not set. Failing date setting, e.g. due to a long power cut.
Typical repair cost £0-£120 (including labour)

DIY fix possible

Locate the display panel on the front of your boiler.Access the settings menu to manually input the current date and time.Save the settings and restart the boiler to clear the fault code.If the settings do not stick after repeated power off/on, contact a technician to check the internal battery.

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Worcester Bosch models that show the 8/0/3 fault code

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

Source

Worcester Bosch 8/0/3 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