hi i have got a problem with a ferroli falcon i was asked to look at it by a landlord me being about the 5th engineer.the problem was the boiler was going through its sequences on hot water fan,aps,ignition but no flame,so i checked the gas valve and found it to be faulty and renewed it.on doing this the burner would ignite
then lockout after ten seconds or so then it would try to relite a couple of times then go to lockout also heating wasnt working either.i checked electrodes leads etc anyone got any ideas 

