If you do come up with a schematic. I'd appreciate if you would post the diagram. I am trying to come up with the same thing myself to substitute for the BLT. In my inexperience, I am looking at Honeywell Aquatrol Contol Panel AQ2504B2,
http://www.alpinehomeair.com/related/69-1982.pdf to run all my wiring through, as it has both 115v and 24v output terminals. I have the L6008A SPST aquastat for the pressurized storage tank, which will be heated by my Solo Innova. I am trying to work it just like Woodnotoil describes above. In my case, for the aquastat to be part of a circuit to turn or off a Grundfos circ pump, a two position 24v Honeywell motorized ball valve, and the forced hot air furnace fan. And if the thermostat is calling for heat and there is no 150+ degree water available from either the boiler, or storage, to switch on the whole forced hot air furnace. I don't know if the wiring can all be done within that Aquatrol panel or if I need to add something additional to be the equivalent to the BLT. Anybody know?
Mike