BoilerFaultCodesVokera AL34 Fault Code
The Vokera AL34 fault code means: your boiler has stopped working because the fan that clears away waste gases is not spinning at the correct speed or its signal isn't being picked up by the system.. It appears on 8 Vokera models in our database.
Technical description: Fan tacho signal fault
What causes the Vokera AL34 fault?
This fault occurs when the boiler's internal computer tries to spin the fan but doesn't receive the correct feedback signal to confirm it is moving safely. The most common reason is that the fan motor has physically burnt out or the delicate electronic sensor inside the fan has failed, preventing the boiler from safely venting waste gases. In some cases, it can also be caused by a loose connection or a fault on the main control board failing to process the signal.
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 AL34 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Vokera AL34 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