BoilerFaultCodesTechnical description
No Heating demand from external controls 24V
What causes this fault?
This code appears because the boiler is powered up and ready to work, but it hasn't received a signal from your thermostat or timer to start heating the house. It is often caused by a simple issue like dead batteries in a wireless thermostat or the heating schedule being set to 'off' on your programmer. In some cases, it may indicate a wiring issue or a hardware failure between the external controls and the boiler's circuit board.
This is frequently seen during the first cold snap of autumn when homeowners turn their heating back on only to find their thermostat batteries have died over the summer.
DIY fix possible
Check that your room thermostat is turned up higher than the current room temperature.Ensure your programmer or heating clock is set to 'On' or 'Auto'.Replace the batteries in your wireless thermostat if the screen is blank or showing a low battery symbol.