High
F12 on Ferroli iBoiler 28

Your boiler is having trouble measuring the temperature of your hot water, which usually means your taps will only run cold.

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

DHW sensor error

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

F11View →F14View →A06View →

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