5 red flashes High

Baxi 5 red flashes Fault Code

Also written as 5REDFLASHES — same fault.

The Baxi 5 red flashes fault code means: your boiler's internal memory chip has developed a communication fault, meaning the control board can no longer read its essential settings.. It appears on 22 Baxi models 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: Parameter storage unit (PSU) error.

What causes the Baxi 5 red flashes fault?

This fault occurs when the small plug-in memory chip on the main control board fails or loses its connection. It is usually caused by an electrical glitch or internal wear and tear that prevents the boiler from identifying its own model and safety settings. Without these specific instructions, the boiler shuts down immediately as a safety precaution.

Typical repair cost £120-250 (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 5 red flashes fault code

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

Source

Baxi 5 red flashes 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