How much does it cost to fix Saunier Duval error code E12?

Typical repair cost for the Saunier Duval E12 fault is £120-200 including labour.

E12 Medium

Saunier Duval E12 Fault Code

Q: What does the Saunier Duval E12 fault code mean?

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.

The Saunier Duval E12 fault code means: 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.. It appears on 4 Saunier Duval models in our database.

Technical description: DHW thermistor (NTC) fault

Typical repair cost £120-200 (including labour)

Engineer required

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

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Saunier Duval models that show the E12 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Saunier Duval E12 fault code information on this page is sourced and cross-checked against the official Saunier Duval service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026