High Lockout
10-64 on Daikin D2CND

Your boiler has detected a communication issue with its internal gas control system and has shut down as a safety precaution.

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

Gas valve circuit error, try resetting the boiler

What causes this fault?

This fault occurs when the boiler's main computer loses the ability to safely regulate the flow of gas to the burner. It is typically caused by an electrical failure within the gas valve itself or a breakdown in the wiring that carries signals between the valve and the control board. For safety, the system instantly stops operating because it can no longer guarantee the correct amount of fuel is being delivered.

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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