Your boiler has detected that one of the control buttons is stuck or is being pressed for too long, preventing you from changing settings.

DIY fix possible

Gently press and release each button on the control panel to see if any feel stuck or 'mushy'.Wipe the control panel with a dry, lint-free cloth to ensure there is no debris or sticky residue trapping a button.Perform a power reset by turning the boiler off at the fused spur switch for 30 seconds, then turning it back on.