My Puma 100e CH wont work?

my central heating was working a wee while ago but now it wont work at all. I can get hot water to work at all times but i just cant get my central heating to work. Theres a timer on the boiler and i have no idea how to use it and have no manual for the bl**dy thing.

I really hope someone has some sort of idea how to get my heating to work cause im bl**dy freezing....