Single solar tank with internal heat exchanger. Click image to enlarge. Internal heat exchanger solar water tank preheating conventional tank. Click image to enlarge. Internal heat exchanger solar water tank with modulating tankless heater. Click image to enlarge.
     
solar space heating diagram solar hydronic heating diagram iSolar controller
External solar heat exchanger tank with boiler backup to radiant floor. Click image to enlarge. External solar heat exchanger w/ large storage tank to space heating coil. Click image to enlarge. Dual coil solar water tank w/ boiler backup feeding radiant through HydroLink. Click image to enlarge.
     
hydronic solar heating diagram diagram of hydronic solar heating drawing of solar hydronic heating
Solar tank providing heat to HydroLink then to space heating loads. Click image to enlarge. Solar tank turned off, heat fed from boiler through HydroLink. Click image to enlarge. Solar storage feeding indirect heater through Hydro Separator w/ boiler backup. Click image to enlarge.
     
picture of hydronic heating (solar) image of solar heating system  
External heat exchanger with solar storage tank. Click image to enlarge. Solar Drainback system with boiler backup. Click image to enlarge.