High Lockout
S.16 on Glow-worm Flexicom cx

Your boiler is staying in a cooling-down mode because it thinks the air fan is still spinning when it should have stopped.

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

fan overrun

What causes this fault?

This fault occurs when the boiler's control board detects that the fan is still rotating even though the power to it has been cut. The most common reason is a communication error between the fan and the main circuit board, often caused by a failing fan motor or moisture affecting the sensitive electronic sensors.

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

S.32View →

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