High Lockout
411 on Ideal Response SE

Your boiler's internal computer has suffered 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

Internal failure - electronic

What causes this fault?

This fault occurs when the boiler's main control board suffers a hardware malfunction, preventing it from processing instructions or safety checks. The most common reason is a component failure within the circuitry, often caused by age or a power surge that disrupts the board's internal communication.

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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