BoilerFaultCodes Test4 High
Boiler Fault Code Test4
Also written as TEST4 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Test4 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has failed to light the flame after several attempts, meaning it cannot provide you with any heating or hot water. (As reported on Vokera Pinnacle)
Pick your boiler brand for the Test4 fix
Source
Information for the Test4 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