High Lockout
E10 on Keston C36

Your boiler’s internal computer has encountered a critical electronic failure and cannot safely operate 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

Control box errors - possible faulty control box.

What causes this fault?

This fault occurs when the boiler's central control board suffers a hardware malfunction or loses its ability to communicate with the internal sensors. The most common reason is a component failure on the printed circuit board (PCB) or a loose connection within the main wiring harness. Because the brain of the boiler can no longer verify that it is operating safely, it automatically shuts down as a precaution.

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

E11View →

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