BoilerFaultCodesAlpha F4 Fault Code
The Alpha F4 fault code means: your boiler is simply performing a routine safety clear-out to remove any remaining exhaust gases after finishing a heating or hot water cycle.. It appears on 1 Alpha model in our database.
Technical description: Post ventilation in progress. Fan in function after a request for domestic hot water or central heating in order to evacuate residual fumes.
DIY fix possible
Wait for a few minutes to allow the fan to finish its cooling cycleMonitor the display to see if the code clears and the boiler resumes normal standby modeEnsure there are no obstructions to the external flue terminal
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Alpha models that show the F4 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Alpha F4 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 7 July 2026