BoilerFaultCodes 338 F0 High
Boiler Fault Code 338 F0
Also written as 338F0 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 338 F0 appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is repeatedly trying to start up its flame but failing to detect that water is circulating through the system, causing it to lock itself to prevent damage. (As reported on Worcester Bosch Greenstar CDi Compact)
Pick your boiler brand for the 338 F0 fix
Source
Information for the 338 F0 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