How much does it cost to fix Ideal error code S3?

Typical repair cost for the Ideal S3 fault is £120-350 including labour.

S3 High

Ideal S3 Fault Code

Q: What does the Ideal S3 fault code mean?

Your boiler's burner has shut itself down for safety because it failed to light or stay lit correctly.

The Ideal S3 fault code means: your boiler's burner has shut itself down for safety because it failed to light or stay lit correctly.. It appears on 1 Ideal model in our database.

Technical description: Burner lock indicator. Feeds signal from lockout terminal on burner control box to lock out indicator on boiler control panel.

Typical repair cost £120-350 (including labour)

DIY fix possible

Check that your gas or oil supply is turned on and you have credit on your meter.Locate the reset button on the burner control box and press it once.Check for any obvious blockages in the flue pipe outside.

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Ideal models that show the S3 fault code

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

Falcon Gte Repair: £120-350

Source

Ideal S3 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.

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