Your boiler is reporting that a separate heating control, such as a thermostat, timer or hot water cylinder sensor, is currently asking it to switch on, which is usually normal and not a sign of damage.

DIY fix possible

Check your room thermostat and programmer or timer to confirm they are set as you expect, and that the heating is not scheduled to run when you do not want it to.Look at any hot water cylinder thermostat and check the cylinder is not calling for heat when it is already warm.Make sure any zone valves or external controls are not stuck open or on, then wait a few minutes and see whether the code clears by itself.If the code stays and the heating runs constantly, switch the boiler off at its isolator, wait 10 seconds, switch it back on, and check again. If it persists, contact a Gas Safe registered engineer.