BoilerFaultCodes.com
09 High Lockout

Your boiler has stopped working because it has detected a problem with the gas supply or the internal valve that controls the fuel flow.

Call an engineer soon

Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Gas valve circuit / low pressure error

What causes this fault?

This fault occurs when the boiler's control system loses its electrical connection with the gas valve or detects that the valve isn't opening correctly. The most common reason is a hardware failure within the valve itself, though it can also be caused by a faulty control board sending the wrong signals. Essentially, the boiler has shut down because it can no longer safely manage the flow of fuel needed to create a flame.

Typical repair cost £180-350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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