BoilerFaultCodes 105 Low
Boiler Fault Code 105
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 105 appears across 2 boiler brands and 5 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 low water pressure and is automatically running a seven-minute process to remove trapped air from the system before it resumes normal operation. (As reported on Atag Q 25CR)
Pick your boiler brand for the 105 fix
Source
Information for the 105 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