High Lockout
F15 on Ferroli Modena HE

Your boiler has stopped working because it cannot properly control the fan that removes waste gases from the system.

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 problem – tachometer signal interrupted fan connection or damaged debris in fan. You need to check and clean fan debris

What causes this fault?

This fault occurs when the boiler's computer cannot detect the speed of the fan, often due to a build-up of dirt or debris inside the fan's blades. If the fan cannot spin effectively or communicate its speed back to the system, the boiler will shut down as a safety precaution to prevent dangerous fumes from staying inside the unit.

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

A03View →

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