Medium
E12 on Saunier Duval Thelia

Your boiler has lost the ability to accurately measure the temperature of the hot water it produces, so it has turned off the hot water supply to prevent overheating.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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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

DHW thermistor (NTC) fault

Engineer required

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

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Related fault codes

E13View →

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