Hi I'm trying to connect up a wet underfloor system to a ferroli combi boiler it's wired through a poly pipe single zone wiring master , the question is how do I wire up a switch live from the wiring centre to the boiler when the boiler needs a perm live to feed hot water on demand can't see anywhere on the boiler to connect to apart from the obvious l/n/e and the n/closed loop which is low voltage .I spoke to there technical dept I might as well phoned good Samaritans much use as a chocolate fire guard he told me to take out the live feed to the boiler and take an additional wire from the wiring centre marked 230v and join in a connector inside the fused spur tried that knew I was wasting my time nothing need perm live all the time hope someone can throw some light on this problem rob