John Pughe is a long-time colleague of mine and a true hydronics professional. He recently sent me an “as installed” and “as corrected” schematic for a hydronic heating system with twin 200,000 Btu/hr mod/con boilers, and 15 zones, each powered by its own circulator.
Assuming that the aquastat is operating correctly, and that essential details are all present and correctly installed, why is the system behaving this way?
A schematic, very similar to the one below, appears in a manufacturer’s installation manual. It represents the manufacturer’s recommendation for installing a two-zone system. Can you identify at least five things that could be changed to improve this system?