So I have a question about my pipeing. The way I have everything setup now I have two 007-f5s in line, one that acts as the system circulator and one that used to be the system circulator before my wood boiler was installed and sits on the cold water return on my oil boiler. I have a 3-way motorized ball valve that switches between wood & oil. I'm pretty sure the circulator on the oil boiler is now redundant when I am running on oil. In fact if I understand correctly it's boosting the system circulator and probably over pumping everything. The other thing is that blue item in the diagram is a thermostatic valve, seems like the circulator on the oil boiler would be working against it... I do seem to be getting some cavitation when running on oil that I don't get when I'm on wood, that's the biggest reason I'm questioning if it should be there or not. The double pumping effect probably isn't terribly efficient either. So, should yank that pump?