Multiple thermostats on oil heating system with stove input

I have a thermal store heated by a boiler with its own thermostat. I also have a stove with a back boiler. The stove heats water in a separate tank. There is a thermostat on this second tank that pushes hot water over to the store tank when it's hot. It's a closed loop and goes through a heat exchanger before returning to the stove. The thermal store has a loop going into the heat exchanger and there is a thermostat on the stove pipe, that when it detects hot water activates a pump on the thermal store side, taking the heat from the stove circuit. The boiler normally heats the thermal store temperature to about 67 degrees. For the heat exchanger to work correctly, and take heat from the stove circuit, what should the other two thermostats be set to? Thanks