Modular Hydronic Heating System Core

A modular hydronic system core system and method includes a hydronic fluid flow conduit with closely spaced tees and distribution supply and return portions on a substrate. A supply manifold is coupled to branch feeders that support a circulator pump or zone valve. An ECM circulator along the conduit includes a Bluetooth transmitter to capture and transmit fluid flow rate and pressure. A return manifold includes branch returns with purge/shutoff valves. The branch feeders and returns are connectable to a distribution system having heating elements. Air and dirt separators, and an iron remover remove air, dirt and iron from the fluid. An expansion tank bracket supports a pressure gauge and expansion tank. A zone relay is coupled to the ECM circulator and zone valves on the branch feeders, and includes thermostat terminals. The zone relay captures inputs from the thermostats to control operation of the ECM circulator and zone valves.