BoilerFaultCodesVokera A18 Fault Code
The Vokera A18 fault code means: your boiler's internal computer memory is not communicating correctly with the main control board, preventing the system from starting.. It appears on 1 Vokera model in our database.
Technical description: INCORRECT EEPROM SIGNATURE EEPROM not recognised by the processor
What causes the Vokera A18 fault?
This fault occurs when the boiler's central brain fails to read the permanent memory chip that stores its specific operating instructions. It is usually caused by a hardware malfunction within the electrical circuitry or a communication failure between the memory chip and the control board. Because the boiler cannot verify its own identity or settings, it shuts down for safety reasons.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Vokera models that show the A18 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera A18 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