High Lockout
E09 on Main Eco Compact

Your boiler has lost its electrical connection to the gas supply unit, meaning it cannot ignite to provide heating or hot water.

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

Gas valve connection error

What causes this fault?

This fault occurs when the boiler's main control board loses the electrical signal required to operate the gas valve. The most common reason is a loose or damaged wiring connection between these two parts, or an internal electronic failure within the gas valve itself.

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.

Find a Gas Safe engineer
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Related fault codes

E109View →E28View →

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