Vokera A12 Fault Code
The Vokera A12 fault code means: your boiler's computer memory has encountered a software error and can no longer communicate correctly with the main control board.. It appears on 1 Vokera model in our database.
Technical description: Incorrect EEPROM signature
What causes the Vokera A12 fault?
This fault occurs when the boiler's internal memory chip loses its identity or fails to share the correct security handshake with the main control board. The most common reason is a physical failure of the memory component on the circuit board, often caused by an electrical surge or simple component degradation over time. Because the boiler no longer knows its own operating parameters, it shuts down as a safety precaution.
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 A12 fault code
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Source
Vokera A12 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