High Lockout
F11 on Glow-worm Ci Plus

Your boiler's main control board and the display panel are having trouble talking to each other, which has caused the system to stop working.

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

User interface / Main PCB communication fault

What causes this fault?

This fault occurs when the data connection between the boiler's main brain and the control panel on the front of the unit is broken. The most common cause is a loose internal wire or moisture damage affecting the delicate circuit boards, preventing them from sending signals to each other. Because the control panel can no longer 'talk' to the engine of the boiler, the system shuts down as a safety precaution.

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

F12View →F13View →

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