The selection dial will be driven around by a small electric motor - cams and switches will control the rotation - it may for instance rotate to a position where water needs to be heated so the motor stops until the - - water at required temperature - - condition is met - and then the motor moves on to the next step.
Other than reporting a rotating dial you do not claim a fault with your machine - I suspect that it's always been that way and you've not noticed it before. If everything else is OK with your machine then you have nothing to be concerned about. The selection dial turns to make everything work as it should.
Good luck...
Delia Smith, September 2014
