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

Typical repair cost for the Saunier Duval Lockout fault is £150-350 including labour.

Lockout High

Saunier Duval Lockout Fault Code

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

Your boiler has stopped working because it cannot successfully start or maintain a flame, so it has safely shut itself down to prevent gas from building up.

Also written as LOCKOUT — same fault.

The Saunier Duval Lockout fault code means: your boiler has stopped working because it cannot successfully start or maintain a flame, so it has safely shut itself down to prevent gas from building up.. It appears on 1 Saunier Duval model in our database.

Technical description: Appliance goes to lockout - check if burner is cross lighting, check sensing lead and electrode continuity, 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 Lockout fault code

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

SD 30e Repair: £150-350

Source

Saunier Duval Lockout 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