High Lockout
15 on Remeha Quinta 30

Your boiler’s internal computer has developed a serious electronic fault and can no longer control the heating process safely.

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 failure

What causes this fault?

This fault occurs when the boiler's internal computer suffers an electrical failure and can no longer process data or safety checks correctly. The most common reason is a short circuit or component degradation on the printed circuit board, often caused by age or power surges from the mains supply.

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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