I'm a newbie to the group and I have read the FAq on how to balance a
heating system.

My question is should the inlet or outlet valve on a radiator be used
as the LSV?

All of the radiators in the house we have had extended were without
the caps described in the FAQ and all valves were fully open. This
means that the radiator at the far end of the house, which I assume is
last in the circuit, never gets more than luke warm.

Any help would be greatly appreciated.

Keith.