How can I turn my Volkera excell 80sp on again?

Hi, I have a Volkera excell 80sp.
I shut off accidentally the gas supply while the central heating was working. Although I opened the gas immediately the central heating stopped of working, neither hot water or heating. I've tried to turn it on relighting the pilot following the manual but it doesn't work... if it exists, does somebody know if there's any way to reset/restart the boiler? One curious detail, when I press the ignitor button I don't see any spark, but as far as I remember I've never seen a light/flame through the pilot sight glass.
I'll appreciate any help, it's very cold these days to be without heating.