will this timer :- http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=68654&id=27967
be ok to use with my vaillant VCW GB 242 EH combi boiler?
what does voltage free contacts mean exactly?
my current timer is a randall 103
it has a live,neutral & earth going to a 13 amp plug
it then has...