High Lockout
30 on Intergas Rapid 25

Your boiler's internal control board cannot safely operate the gas valve, preventing the system from firing up for 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

Relay gas valve defect

What causes this fault?

This fault occurs when the boiler's main control board detects a hardware failure in the electrical relay that controls the gas supply. It is essentially a safety conflict where the board can no longer reliably open or close the gas valve, forcing the system to shut down to prevent potential safety risks. The root cause is typically a component failure on the circuit board itself or a communication error between the board and the gas valve.

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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