High
LOCK OUT on Halstead Hero

Your boiler has stopped working for safety reasons and needs a manual reset to attempt to start up again.

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

Boiler failure to light or safety shut down; requires reset by turning the boiler thermostat fully anti-clockwise.

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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Related fault codes

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