Biasi 24s fault?

Hello, i have a biasi 24s boiler, and it wont ignite, the red button comes on, and when i press it , the fan runs but ther is no clicking, like the boiler is trying to light.If i switch to summer setting, red light dims, and nothing runs. pump seems like its running, micro switches ok, water on 1.5 Bar. Could it be APS, or full sequence control unit. i would be greatful for some advice, Many thanks