Unfortunately, these things are almost impossible to remotely diagnose, with so many possible permutations of red wires involved. It needs someone on site, who is reasonably familiar with heating systems, and boiler controls. That person will need to test out those red wires, and identify exactly what goes where.
Just randomly swapping the wires around, and hoping for a fix, simply will not work, but more importantly might cause further damage.
Your young electrician, ought to have begun the job, by marking those reds up with numbers or other means to differentiate them, so if the worst happened, then he could at least back track, to the original control.
