What the manual says
Manufacturer manualPower ON. Boiler is in service. If no other LED’s are illuminated, the appliance is awaiting a demand for heating or hot water.
From this model's manual
Verified against the Halstead Finest Gold ISM installation & service manual.
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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