3 green flashes Low

Baxi 3 green flashes Fault Code

Also written as 3GREENFLASHES — same fault.

The Baxi 3 green flashes fault code means: your boiler has briefly lost its flame and is trying to restart itself, which is often a temporary glitch that might resolve without any action.. It appears on 27 Baxi models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Temporary flame loss. Boiler will self reset, if fault continues you will see 3 red flashes.

What causes the Baxi 3 green flashes fault?

This fault occurs when the boiler's internal sensors detect that the flame has unexpectedly gone out while the unit was supposed to be firing. The most common reasons include a slight instability in the gas supply or a build-up of carbon on the sensor that monitors the flame. Because it is often caused by a fleeting disruption, the boiler will attempt to relight itself automatically before locking out.

Typical repair cost £100-250 (including labour)

DIY fix possible

Monitor the boiler to see if it clears the fault and restarts automaticallyIf the fault persists and turns into a solid red light, try a manual resetCheck that your gas pre-payment meter (if applicable) has credit

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Baxi models that show the 3 green flashes fault code

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

Source

Baxi 3 green 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