High Lockout
30 on Ideal Maximiser SE

Your boiler has detected an issue with the electrical power supply to the unit while it was running.

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

Check the mains supply during operation.

What causes this fault?

This fault occurs when the boiler detects an unstable electrical signal or a sudden drop in voltage while it is firing. It is usually caused by a loose connection in the internal wiring, a failing control board, or an issue with the electrical circuit providing power to the unit.

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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