Problem with Worcester Bosch 24i..............?

I had to turn the boiler and water off today when I was having some work done in my bathroom. I switched it back on at the mains and the light is on but there is no heating or hot water. Previous threads have said to press the reset on on the top of the boiler, towards the left hand side, about an inch from the front. However, I have the same model but there is no reset on on the top!! All I can see is 2 twisty knob things - one brown and one with a red lid over it. There is no on! Please help.