I have an appointment to get a quote to put a Waterfurnace or Bard. When I mentioned a flow center he got really annoyed at the idea of a non pressurized system. he also mentioned that very few manufactures will warranty a system if it is not a sealed closed loop. I keep reading that flow centers reduce service calls and work just fine. This guy has a great rep in the area and is somewhat of a perfectionist. I have 1800 feet of pipe buried and getting ready to manifold in the basement 3 circuits. two questions, 1. can the compression type manifolds from B&D (see picture) be pressurized or do I have to send these back, 2. are QT flow centers supported by geothermal HP manufacturers?