how to set my boiler and thermostat up?

i have the Glow-worm ultimate boiler system please could any body tell me how to set the system up as its cold and boiler keeps turning off and no heating and its very cold at the moment,i need to know how to set up the timer too as i dont have a manual im thick probably i always thought it was set to constant but there is blue and red buttons on a timer dial and the thermostat downstairs and i just want the boiler to fire up but keeps shuttting down leaving no heating for me and my children.all i wanmt to do is to be able to turn on the thermostat downstairs and heating when needed so basically its constantly on pllease help as the tempreture is dorping at the moment and i have five very young children.
many thanks any correspondance is greatly appreciated .many thanks carla.