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 software or connection error, meaning it can no longer remember its correct settings to operate.. It appears on 27 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 boiler's internal memory chip fails to communicate with the main control board, similar to a corrupted file on a computer. It is usually caused by a hardware failure within the chip itself or a loose physical connection on the circuit board that prevents the boiler from reading its essential operating instructions. Because the boiler no longer knows its own safety limits or settings, it shuts down immediately as a precaution.

Typical repair cost £120-350 (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 27 April 2026