High Lockout
F16 on Ideal Logic Max Combi

Your boiler has detected an internal electrical problem with the gas control valve, meaning it cannot safely 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 Fault: Check gas valve wiring, if OK replace gas valve

What causes this fault?

This fault occurs when the boiler's main control board loses the electrical connection with the gas valve or detects that the valve is not responding correctly. It is usually caused by a component failure within the gas valve itself or a faulty connection on the circuit board that prevents the boiler from safely controlling the flow of gas.

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

F1View →L1View →L2View →

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