High Lockout
E1-65 on Daikin D2CND

Your boiler's internal electronic self-monitoring system has detected a technical fault and has shut down as a safety precaution.

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

Internal SCOT system error. Perform reset if needed

What causes this fault?

This fault occurs when the boiler's internal computer system fails to communicate correctly with the safety controls that monitor the gas flame. It is usually triggered by a communication error on the circuit board or a failure in the electronic calibration system that ensures the boiler is burning gas safely. Because the boiler cannot verify that the combustion process is stable, it will shut down to prevent incorrect gas mixtures.

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

E1-64View →

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