I did not stay at a Holiday Inn last Night ( you have been warned).
So there's no confusion, I installed the bypass loop (balancing loop) but not a dump zone. The bypass loop, as I understand it, can be used to raised the internal tempurature of the boiler by returning water to the supply line directly from the return line, bypassing the boiler vessel. The higher boiler temperature ensures adequately hot DHW from the boiler coil. At the time of my install, I figured a few extra feet of pipe and a couple of valves were within the budget and I'd was already fitting pipe. I also would rather not need it and have it. I don't use the hot water coil, keep the loop closed and haven't had to mess with it.
The dump zone is a differnet animal entirely although the controler for the dump zone sits in a well on the balance loop, as shown in the instruction manual (such as it is). It needs to be wired to a circ pump on a dump zone, which would activate in a high temprature situation.
Hopefully the old hands here will correct me if I'm wrong. Not that thats ever happened