BoilerFaultCodes F.326 High
Boiler Fault Code F.326
Also written as F326 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.326 appears across 1 boiler brand and 3 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 multiple internal valves or pumps are failing to respond, which means it cannot safely move water around the system to provide heating or hot water. (As reported on Vaillant ecoTEC plus)
Pick your boiler brand for the F.326 fix
Source
Information for the F.326 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 7 July 2026