BoilerFaultCodes 2.0 Medium
Boiler Fault Code 2.0
Also written as 20 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 2.0 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 is currently in a manual testing mode used by engineers to check its performance rather than a standard fault, meaning it is not operating normally for your home heating. (As reported on Worcester Bosch ZB 7 27 HE)
Pick your boiler brand for the 2.0 fix
Source
Information for the 2.0 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