baxi solo 2 wont light?

Hi can any one help me? we are freezing.
I have a Baxi Solo 2 boiler and when I turn it on it wont fire up. All the lights come on including the pilot led but the burner led doesnt light up and the boiler just keeps clicking and doesnt fire up, I presume the clicking noise is the boiler trying to fire but its a bank holiday here today so I'd rather not call out a plumber...