The Phoenix Evolution from Heat Transfer Products looks to be a great all in one device for you home heating, domestic hot water, and solar preheating. Everything is preplumbed for you so all you have to do is hook it up to your hot water heat system, your domestic hot water system and you can even have one with an internal coil to preheat your tank water with an outdoor solar panel. Looks to be a great system that will work well in cramped utility rooms and take the guess work out of plumbing a solar hot water system effectively. Check out their other heating products as well.