potterton performa 24 reset button?

Hey there

Woke up today to no hot water/heating. We have had this problem before, and the pcb board was replaced (about two years ago). Pressure is fine (I upped it with the filling loop but no joy), so now I want to check that it’s not simple overheating before I part with some cash! Problem is, since the work was done last time, the reset button seems to have vanished. If anyone could shed any light on this, it would be greatly appreciated!

Cheers.