Ideal Mini C24 Boiler Problem?

Last night the boiler was working ok, went to switch the boiler onto constant this morning only to find that it wont fire up, water switch and heating switch are both about mid way between min & max, when I turn the boiler onto constant by way of a seperate timer type controler a sound coming from the boiler sounds like a car with a faulty starter motor, it turns and turns but does not fire up, there is no pilot light, the gas is present as ive lit the gas stove, the pressure on the boiler reads 1 bar, the fault light is showing a flashing green light, it is not a rapid flash, can any one help please. Cheers.