BoilerFaultCodesVokera A05 Fault Code
The Vokera A05 fault code means: your boiler has detected an internal electrical fault with the component that controls the gas supply, meaning it cannot safely ignite.. It appears on 1 Vokera model in our database.
Technical description: Gas valve relay error
What causes the Vokera A05 fault?
This fault occurs when the boiler's main control board detects a failure in the electrical circuit that opens and closes the gas valve. The most common reason is that the physical relay on the circuit board has worn out or become stuck, preventing the boiler from safely managing the flow of fuel. Because the system can no longer guarantee the gas will shut off correctly, it stops operating 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 A05 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera A05 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