BoilerFaultCodesTechnical description
No heating demand from external controls
What causes this fault?
This code appears when the boiler is healthy but is currently sitting in standby mode because it hasn't received a signal to start. It physically occurs when the electrical circuit between your external controls and the boiler remains open, suggesting your timers or thermostat are either satisfied or switched off. Common culprits include dead batteries in a wireless thermostat or a programmer set to the 'Off' position.
This is often reported during the first cold snap of autumn when homeowners forget to turn their room thermostats up or replace the batteries after a summer of disuse.
DIY fix possible
Check that your room thermostat is turned up higher than the current room temperature.Ensure your programmer or heating timer is set to 'On' or 'Auto'.Replace the batteries in your wireless thermostat if the screen is blank or showing a low battery symbol.