Does the schematic accurately represent your actual set-up? I think there are problems with the schematic. First, the return from the heating loop should enter near the bottom of the heat source. Second, the cold water should also go directly to the heat source which I assume is a water heater of some sort, so redraw the schematic with the heat loop return line continuing straight into the side of the heat source and the cold water line from supply passing right by the hot side of the heating loop and going into the heat source. There must be a cold water line going to the heater, and that's all that's needed. Is the heat source providing hot water for other uses in the house? Eliminate the pressure relief valve entirely as there should be one on the heat source. One circulator is more than sufficient for 300' of PEX line in the slab, so you can eliminate two pumps and tie all three loops together in parallel (or series if you want). |