High Lockout
E15 on Baxi 600 Combi (range)

Your boiler has detected an internal communication error with the part that controls the gas supply, meaning it cannot ignite safely to provide heat 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 command fault.

What causes this fault?

This fault occurs when the boiler's main control board loses the ability to properly communicate with the gas valve that regulates fuel flow. It is typically caused by a loose internal connection, a failing circuit board, or a mechanical breakdown within the gas valve itself, preventing the system from safely releasing gas for ignition.

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

E12View →E13View →E110View →

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