I am going to install my new woodgun 180 wood/oil boiler in the near future and already bought a 160F Danfoss Thermic Valve for return water protection. How does a Termovar loading unit compare to these, what are the pros/cons/ . If a loading unit is better is it just a matter of adding a circ. pump and aquastat to the bypass with the thermic valve to build a loading unit. My system currently has 1 circ. pump and 5 zones with a conventional wood/oil boiler.