Hi David,......I'm in the process of getting the kinks worked out right now.
All I have is a roof-top collector (~3.5gal) , a 12gal hot water tank and a 32gal tank, their hooked in series.
Everything is under house pressure, it just circulates through collector and tanks until it gets to a min. 100F, then it enters house.
One of the problems I have right now is ,when up to temp. the system is heating my cold water side. But I'm going to put in a check valve on the cold out ,I think this will solve the problem.
Here's a crude drawing
really pretty simple ......
I'm sure you're aware of Garys' site (build it solar) it has all kinds of ideas.........not sure if this was any help or not......good luck......artv