High Lockout
0 4 on Remeha Quinta Ace 25

Your boiler has experienced a power disruption while it was already trying to report a serious internal error, causing it to lock itself for safety.

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 fault: Voltage failure when malfunction causes interlock.

What causes this fault?

This fault occurs when the boiler experiences a sudden power cut or electrical surge at the exact moment it was trying to register a different internal error. This creates a conflict in the boiler's memory, as the control board cannot safely confirm why the system shut down. It is essentially a safety 'double-lock' that prevents the boiler from firing up until the electrical integrity of the control unit is verified.

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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