No Flashes (after 15 seconds) High

Baxi No Flashes (after 15 seconds) Fault Code

Also written as NOFLASHESAFTER15SECONDS — same fault.

The Baxi No Flashes (after 15 seconds) fault code means: your boiler has failed to detect a flame or a temperature reading, meaning it has completely shut down for safety.. It appears on 1 Baxi 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: Temperature Sensor / Gas Flame Detection fault. Replace P.C.B.
Typical repair cost £280-450 (including labour)

Engineer required

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

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Baxi models that show the No Flashes (after 15 seconds) fault code

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

Source

Baxi No Flashes (after 15 seconds) fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026