Whats wrong with my boiler? do I need to get a plumber in?

Hiya we have a Ferolli falcon boiler and we've just returned home (we left the boiler off for 4 days over xmas) and when we try and turn the heating on the boiler starts up but then cuts out after about 1 min. It then tries again only to cut out after only 5 seconds. The boiler was only serviced about 2 months ago. Please can you help? We don't even have the boiler manual as one of the plumbers took it with him and never returned it.