How to set clock on Worcester Bosch Greenstar 28i Junior?

Hi there, our heating doesnt go off when the time goes past the time I set it for. I cant find clock setting instructions in the manual so am not sure how to address the fault - its only started after I changed the time. I know there is the dial clock and also a clock with hands in the centre but these dont seem to work in tandem, the dial clock (with raised setting bars) is correct and i moved the hands on the central clock to reflect the correct time yesterday but its still stays on after the time it should go off.

Can anyone tell me what I'm doing wrong?

Thanks