A77 High

Vokera A77 Fault Code

The Vokera A77 fault code means: your boiler's internal computer is receiving an unexpected temperature reading from a sensor, which has caused it to stop working for safety reasons.. 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: Low temperature thermostat fault
Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Vokera models that show the A77 fault code

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

Source

Vokera A77 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 7 July 2026