High Lockout
E12 on Baxi Avanta

The main computer inside your boiler has encountered a technical failure and is unable to control the heating process.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Printed circuit board (PCB) Fault

What causes this fault?

This fault occurs when the boiler's internal computer suffers a hardware failure and loses its ability to communicate with the sensors or gas valve. The most common cause is a surge in electricity or a slow degradation of the electronic components on the board over time. Because the control board can no longer guarantee the boiler is operating safely, it shuts down the system entirely.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E13View →

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