High Lockout
F.61 on Glow-worm Energy System

Your boiler has detected a communication error with the gas valve, preventing it from safely lighting the burner for heating and 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 control system fault

What causes this fault?

This fault occurs when the boiler's main control board loses the ability to send or receive signals from the gas valve. The most common reason is an internal electronic failure within the gas valve itself or a fault on the circuit board that prevents it from safely controlling the fuel supply.

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

F.27View →F.28View →F.29View →

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