My system will have 4 house zones (Zone valves) a hot tub zone and a future zone for the garage. I have a circulator for the zones and a circulator for the EKO 40. I have one aquastat and an additional zone valve between the storage tanks and boiler (that i'm not sure I even need). My electric boiler will run independent of the WB so that is not in the equation. A friend suggested I use the Taco SR506 switching relay to run the system. Is this a good suggestion? Any tips? Also, I installed the two way zone valve between the storage and boiler so it would close when the house circulator and EKO circulator are running to prevent the water from going into the storage. What are the thoughts on it? Is it necessary?