Your boiler is taking a short, programmed break to prevent it from turning on and off too frequently, which helps protect the internal components from wear and tear.

Anticycling period

What causes this fault?

This occurs when your boiler reaches its target temperature too quickly and shuts down to prevent 'short-cycling,' which wastes energy and puts stress on the components. It usually happens because the heat produced by the boiler cannot be moved away fast enough, often due to thermostatic radiator valves closing as rooms get warm. The boiler is simply waiting for the system water to cool down slightly before it is safe and efficient to fire up again.