How much does it cost to fix Saunier Duval error code Red led flashing?

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

Red led flashing High

Saunier Duval Red led flashing Fault Code

Q: What does the Saunier Duval Red led flashing fault code mean?

Your boiler has stopped working because one of its internal temperature sensors is providing faulty information, preventing it from safely monitoring the water temperature.

Also written as REDLEDFLASHING — same fault.

The Saunier Duval Red led flashing fault code means: your boiler has stopped working because one of its internal temperature sensors is providing faulty information, preventing it from safely monitoring the water temperature.. It appears on 1 Saunier Duval model in our database.

Technical description: NTC sensor faulty

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 Red led flashing fault code

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

Semia Condens F30 E Repair: £120-200

Source

Saunier Duval Red led flashing 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