Halstead Green LED illuminated Fault Code
Also written as GREENLEDILLUMINATED — same fault.
The Halstead Green LED illuminated fault code means: your boiler is working perfectly and is currently in standby mode, simply waiting for you to turn on a tap or adjust the heating.. It appears on 1 Halstead model in our database.
Technical description: Power ON. Boiler is in service. If no other LED’s are illuminated, the appliance is awaiting a demand for heating or hot water.
DIY fix possible
Check your room thermostat is set to a temperature higher than the current room temperatureTurn on a hot water tap to see if the boiler activatesVerify the boiler mode selector is set to the desired 'Heating and Hot Water' position
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Gas Safe Register →Halstead models that show the Green LED illuminated fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Halstead Green LED illuminated fault code information on this page is sourced and cross-checked against the official Halstead service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026