Your boiler is temporarily pausing the heating because an external room thermostat or smart control is telling it not to switch on.

DIY fix possible

Check your room thermostat or smart heating controller (like a Nest, Hive, or wall dial) to ensure the target temperature is set higher than the current room temperature.Replace the batteries in your wireless room thermostat, as flat batteries can block heating signals.Turn your heating controls off and on again to reset the connection between the thermostat and the boiler.