High
F56 – A56 on Ferroli iBoiler 24

Your boiler's internal computer is having trouble setting the correct balance of gas and air needed to burn fuel safely and efficiently.

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

Calibration error / calibration procedure not completed

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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