Please look directly above the hob and you will see these little buttons. If you put your finger on the button which is furthest to the left, the light will turn on. If you put your finger on the next button along, the fan will start up. If you want a stronger fan, then just go along to the next button.
To turn off the fan or the light you have to do the above in the same sequence going backwards. So to turn off the fan you have to press the buttons in turn that bring the fan down a notch and then press the final fan button one last time and it will turn itself off. Crazy but true!!
To turn the light off, again you just put your finger on the light button and it will go off.