Solar heating is typically used in Wisconsin in applications where heat is needed year-round using the tremendous solar resource we have in the summer time. Space heating applications pose a hurdle between the fundamental mismatch of the solar resource summer versus winter.
With this in mind, I typically recommend solar and wood heating together, or wood heating alone. An exception is in very efficient new construction where solar can be financed with the house, can be integrated into the heating and building design, and as a result can deliver a substantial portion of the heat load with a reasonable up-front cost.
If you need service on your solar thermal system (liquid based systems only) I can schedule it as my work load allows. I will typically ask a lot of questions and maybe even ask for some photos up front. This is in an effort to gain as much information about your project and situation as possible before driving to your house. This saves both of us time and saves you money by letting me be prepared for your repair before I make the trip.
There are 40 years worth of solar thermal technology out there, some of it is junk and lots of it is still good technology. I will give you an honest assessment of what you have and an estimate of what it will cost to make it run as designed once again. I have been installing and servicing solar thermal equipment for over 15 years, and have seen most of what Wisconsin has to offer.