BoilerFaultCodesBaxi 1 Green Flash Fault Code
Also written as 1GREENFLASH — same fault.
The Baxi 1 Green Flash fault code means: your boiler has reached the correct temperature and is simply taking a break until it needs to heat up again.. It appears on 27 Baxi models in our database.
Technical description: Boiler temperature reached – no action required
What causes the Baxi 1 Green Flash fault?
This occurs when the water inside the boiler has reached the maximum temperature set by your thermostat or the control dial. The boiler temporarily shuts off the flame because it has successfully done its job, and it will automatically restart once the water temperature drops and needs topping up. It is a normal part of the heating cycle rather than a mechanical failure.
This status is more frequent during autumn and spring when the weather is milder, as the system reaches its target temperature much faster than it would during a freezing winter.
DIY fix possible
Check your room thermostat to see if it is set to the desired temperatureWait for the temperature to drop slightly for the boiler to restart automaticallyNo further action is required as this is normal operation
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Gas Safe Register →Baxi models that show the 1 Green Flash fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Baxi 1 Green 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 27 April 2026