Your boiler has lost its connection to its smart thermostat, meaning it cannot receive instructions on when to turn the heating or hot water on.

DIY fix possible

Check if the batteries in your Alpha Climatic control unit are dead and replace them if necessaryEnsure the control unit is correctly docked or within range of the boilerTurn the boiler off at the fused spur for 60 seconds and then switch it back on to reset the connection