question on wiring for a suprima 50?

i am changing a profile 50 for a suprima 50 the maual say to wire back to the pump from the boiler i presume this is for the over run
do i remove existing wiring from pump to terminal or just add the 3 core to the pump along with existing wiring
kevin

kevin, March 2005

i need a wiring diagram for a s plan heating system

andy hughes, May 2010

yes run 3 core from boiler to pump remove other wires

paul, April 2006