BoilerFaultCodesAlpha 139 Fault Code
The Alpha 139 fault code means: your boiler is currently performing a routine self-cleaning cycle to automatically remove trapped air from its internal system.. It appears on 1 Alpha model in our database.
Technical description: Deaeration in progress
DIY fix possible
Wait for 10 to 15 minutes for the process to complete automaticallyEnsure your heating and hot water are not being used during this timeIf the code does not clear after 30 minutes, switch the boiler off at the fused spur and back on to reset it
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Alpha models that show the 139 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Alpha 139 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026