High Lockout
Gas Valve Fault on Ideal Logic Max Combi

Your boiler has detected an electrical issue with the gas control system and has shut down as a safety precaution.

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

Contact electricity provider

What causes this fault?

This fault occurs when the boiler's main control board sends a signal to the gas valve but does not receive the correct electrical response back. It is typically caused by a mechanical failure within the valve itself, a loose connection in the internal wiring, or a fault on the circuit board preventing it from controlling the fuel supply safely.

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
Search the official register →

Related fault codes

L2View →F2View →FNView →

Related guides you might find useful

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Pilot light keeps going out

Older boilers — thermocouple, draught, gas supply.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →