Potterton Prima F40 doesn't work and display of the timer is empty???

I've just moved in to the house for 2 months. When I moved in, the heating worked properly. But now there is nothing on the display of the timer, the model is Landis & GYR rwb200. And also the light of the boiler is not on. Is the problem about the timer or the boiler? Please advise. I have no idea at all because I've just come from another country and never use the boiler.