Boiler Fault Code F16

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code F16 appears across 4 boiler brands and 9 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected that a flame is still burning inside even though it has been told to turn off, which means it has safely shut itself down to prevent a hazard. (As reported on Glow-worm Xtramax HE)