Mains LEDs High

Saunier Duval Mains LEDs Fault Code

Also written as MAINSLEDS — same fault.

The Saunier Duval Mains LEDs fault code means: your boiler has lost all power and is completely unresponsive, likely due to an internal electrical protection component failing.. It appears on 1 Saunier Duval model in our database.

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: Do not illuminate - check fuse on P.C.B. or replace P.C.B.
Typical repair cost £150-350 (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 Mains LEDs fault code

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

Source

Saunier Duval Mains LEDs 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