High
OVERHEAT LOCKOUT INDICATOR on Halstead Best 20

Your boiler has switched itself off because it got too hot, which is a safety feature designed to prevent overheating damage.

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

Indicator illuminates when the overheat cut off device has operated; requires inspection of the overheat cut off device and potentially a manual reset via the ignition reset button.

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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