What the manual says
Manufacturer manualIndicates if the boiler is receiving power and the thermostat is calling for heat.
From this model's manual
This code was read directly from the manufacturer service manual for this model.
DIY fix possible
Check that your room thermostat is set to a temperature higher than the current room temperatureEnsure your programmer or timer is set to an 'ON' periodCheck if the gas supply is turned on at the meter
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