Alpha d10 Fault Code
Also written as D10 — same fault.
The Alpha d10 fault code means: your boiler is currently displaying its fault history menu rather than a live error, meaning no mechanical failure is actually occurring.. It appears on 2 Alpha models in our database.
Technical description: Fault history reset - when in this menu, press and hold the Summer/Winter button to clear the fault code history
DIY fix possible
Locate the Summer/Winter button on your control panelPress and hold the button down as instructed by your manual to exit the menuMonitor the display to ensure it returns to the standard operating temperature screen
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Gas Safe Register →Alpha models that show the d10 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Alpha d10 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026