F26 High

Boiler Fault Code F26

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code F26 appears across 5 boiler brands and 26 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has shut down because the water is heating up too quickly or hasn't been able to circulate correctly through the system. (As reported on Glow-worm Xtramax HE)

Pick your boiler brand for the F26 fix

Ferroli F26 4 models Glow-worm F26 10 models Heatline F26 8 models Saunier Duval F26 2 models Vaillant F26 2 models

Source

Information for the F26 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026