A quick Google search (and a review of the couple of lines summary you get) gave me these in the first page or two of results:
http://www.justanswer.com/uk-plumbing/3ychp-ferroli-modena-102-fault-boiler-switched-off-just.html
http://www.diynot.com/forums/viewtopic.php?t=61567
http://forums.digitalspy.co.uk/showthread.php?t=1200630
http://howtomendit.com/answers.php?id=109967
Anon
February 2015