High Lockout
41 on Ideal Maximiser SE

Your boiler’s internal control system has encountered a critical electronic failure that it cannot clear itself.

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

Replace the control panel if the malfunction remains after a reset or if the malfunction has occurred before at this control panel.

What causes this fault?

This fault occurs when the boiler's internal computer experiences a major communication breakdown or a physical failure within its circuitry. The most common reason is that the electronic components on the main control board have worn out or suffered a voltage spike, preventing the boiler from safely managing the heating process.

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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