FLASH OFF FLASH High

Baxi FLASH OFF FLASH Fault Code

Also written as FLASHOFFFLASH — same fault.

The Baxi FLASH OFF FLASH fault code means: your boiler is not receiving enough electrical power from the main supply to operate safely.. 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: Voltage less than 180V

What causes the Baxi FLASH OFF FLASH fault?

This fault occurs when the electrical supply entering the boiler drops to a level where the electronic components can no longer function safely. It is usually caused by a wider problem with the local power grid or a failing main circuit board that can no longer process the incoming voltage correctly. In some cases, loose wiring or a faulty external socket can also cause this dip in electrical pressure.

Typical repair cost £100-350 (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 FLASH OFF FLASH fault code

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

Source

Baxi FLASH OFF FLASH 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