Serious thank yous to you for all your help.All new are supposed to be energy A rated, to do this the electronics in the pump knows how much power it required to move x amount water as the thermo valves on the rads shut of this puts a restriction on the water flow causing the to be under more load so it backs the power of as its not needed, all very good on new systems but on an old one that may be a bit clogged up it dont push it through with much omph, if you can get an older style three speed pump that may be better but will require changing the whole unit.
the wiring is just L N E to all of them nowt fancy.
Lynx pumps are identical to the old Grundfos three speed.
I will now be able to discuss it all with a bit more knowledge.
"thermo valves on the rads" I had to laugh at this, not your fault, but we have precisely one in the whole house! On the new rad in the kitchen and we leave it fully open all the time! (It has to heat both the kitchen and the utility.)