High Lockout
E3 on Baxi Avanta

Your boiler's electronic control centre has developed an internal fault and is unable to communicate with the rest of the system.

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 brain suffers a hardware failure or a breakdown in its electronic circuitry. The most common reason is age-related wear to the electrical components on the board, though it can also be triggered by a sudden power surge or moisture getting into the control box.

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.

Find a Gas Safe engineer
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