http://library.plumbase.co.uk/flipbooks/RE/wor350rsf_23136_t/wor350rsf_23136_t.html#p=13
i take it its 2 wires to mains and 2 wires to x4 block where link is on boiler from the recever thanks
http://pdf-cdn.plumb-bay.com/salus-rt500rf-wireless-room-stat-manual.pdf