AL74, AL79 High

Vokera AL74, AL79 Fault Code

Also written as AL74AL79 — same fault.

The Vokera AL74, AL79 fault code means: your boiler has encountered a technical communication or internal sensor error and has stopped working as a safety precaution.. It appears on 3 Vokera models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Reset the boiler. If the fault reoccurs, contact a heating engineer.
Typical repair cost £100-£250 (including labour)

DIY fix possible

Turn the mode selector switch to the 'OFF/RESET' position.Wait for approximately 30 seconds.Turn the switch back to the 'Hot Water' or 'Heating' position to see if the error clears.

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Vokera models that show the AL74, AL79 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Vokera AL74, AL79 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