BoilerFaultCodesTechnical description
No Heating demand from external controls 230V
What causes this fault?
This status occurs when the boiler is powered on and ready to work but hasn't received an electrical signal from your thermostat to start heating the radiators. The most common reason is simply that the room temperature is already higher than the setting on your dial, or the timer is currently in an 'off' period. It can also happen if the batteries in your wireless thermostat have died, preventing the signal from reaching the boiler.
This is very common in autumn when homeowners first try to turn their heating on only to find their thermostat batteries have drained over the summer.
DIY fix possible
Check that your room thermostat is turned up higher than the current room temperature.Ensure your heating programmer or timer is set to 'ON' or 'AUTO'.Replace the batteries in your wireless wall thermostat if the screen is blank or showing a low battery icon.