Strictly speaking, a geothermal heat pump can operate effectively without a manifold header, but there are very good reasons to use one. During the installation process, a manifold header eliminates the necessity of using expensive fusion joint equipment, and eliminates the need for reverse return piping. A manifold system also allows each loop circuit to be independently flushed during filling and purging, independently flow rate verified and adjusted, and independently isolated in the case of failure. We highly recommend the use of a manifold header for most geothermal heat pump installations.