BoilerFaultCodesVokera AL74 Fault Code
The Vokera AL74 fault code means: your boiler has detected an internal electronic error or a communication failure that is preventing it from heating your home.. It appears on 6 Vokera models in our database.
Technical description: Reset the boiler. If the fault reoccurs, contact a heating engineer.
What causes the Vokera AL74 fault?
These codes are triggered by a breakdown in communication between the boiler's internal electronic components or a failure within the main control board itself. It often occurs when the circuit board can no longer process data correctly or when the electrical signals sent between parts become unstable. Essentially, the boiler's 'brain' has encountered an error it cannot recover from automatically, leading to a complete shutdown.
DIY fix possible
Locate the mode selector switch on the front panelTurn the switch to the 'OFF/RESET' positionWait 30 seconds, then turn the switch back to either 'Heating' or 'Hot Water' mode
Find a Gas Safe engineer
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Gas Safe Register →Vokera models that show the AL74 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera AL74 fault code information on this page is sourced and cross-checked against the official Vokera service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026