balancing boiler, passive solar, radiator, and storage tank

Scott Onstott

I'm planning a renovation this spring and my plumbing system will need to be completely redone. Please see attached PDF for my diagram, but please know I really don't know what I'm doing, plumbing-wise.

I have an Esse EWB wood cookstove with boiler (http://www.esse.com/cookers/cookers/multifuel.html) and a "solar boiler" system (http://www.thermo-dynamics.com/solar_boiler.html) as heat sources. I figure I could also use an electric element in the water storage tank that I could manually turn on its circuit breaker when there's no sun and no fire. The Esse stove makers claim that with 15000 btu/h I could heat my DHW and run one radiator, which I am keen to do. Plumbing this with a radiator and combining it with the passive solar boiler system is where I am lost.

I'd like to do a gravity hot water system as I'd prefer not to power a 12V pump if at all possible on the radiator circuit. However the pump might be necessary as the radiator is on the same floor as cookstove boiler.

The passive solar panel comes with a small photovoltaic panel that powers its pump and that should work fine as it only works when the sun is shining and heating the water in the panel. It has a heat exchanger with pump and electronics built in so all I have to do is run domestic water through other side of exchanger to storage tank.

The beauty of this combined solar boiler/cookstove boiler system is I will get almost all my year round hot water "for free". However making it work is harder than it sounds.

I would really appreciate some direction from an expert!