Saunier Duval 30e Fault?

Hi, The Boiler Burner light does not come on and there is no ignition. I have ensured there is gas to the system. Have carried out a reset and a full system shutdown. Still the boiler will not ignite? i have made sure the system was requesting for heat. I wonder if the over heat safety device has kicked in? This problem started after a serious leak Developed and the main supply had to be shut off? any help will be gratefull

cheers