1 green Low

Ferroli 1 green Fault Code

Also written as 1GREEN — same fault.

The Ferroli 1 green fault code means: your boiler is receiving power and has gone into a standby mode because the incoming electrical voltage is too low for it to operate safely.. It appears on 1 Ferroli model 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: Mains on/low voltage on
Typical repair cost £0-120 (including labour)

DIY fix possible

Check if there is a power cut or brownout in your local areaEnsure the boiler is plugged into a dedicated socket and not an overloaded extension leadTurn the boiler power switch off and back on again to reset the electronic logic

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Ferroli models that show the 1 green fault code

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

Source

Ferroli 1 green fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026