Medium Warning
F12 on Ferroli Modena HE

Your boiler has lost its connection to the sensor that monitors your hot water temperature, which means you will likely experience cold showers until it is fixed.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Domestic hot water (DHW) sensor fault – sensor damaged, wiring shorted or wiring disconnected – check the wiring

What causes this fault?

This fault occurs when the boiler's main control board can no longer communicate with the sensor responsible for measuring your hot water temperature. The most common reason is that the internal sensor has developed a technical failure or the electrical wiring connecting it to the system has come loose or become damaged.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

A06View →F13View →F14View →

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