I have a Navien CH 180 combi LP heater with one zone in an ~3000 sq ft home in central Pa. I have purchased a used outdoor wood boiler (woodmaster 3300) with one supply and one return, I want to use a small dual coil solar heater tank(100L from duda diesel.com) as an indirect heat exchanger with tempering valve to heat both dhw and my radiant floor loop with the combi as backup if I go out of town for the weekend. can anyone draw a diagram to show me how to do this? The current setup is shown in this link. http://media.blueridgecompany.com/documents/BlueRidge_recommended_install.pdf I called navien and a tech told me it would be impossible to plumb it so the navien unit does not fire, he then told me to call back and ask for another opinion so i'm not quite convinced he understood what I wanted. I cannot afford to pay another winter's propane bill. I need help fast.