The Glitch:

Figure 1 shows the piping layout for an actual installation. It uses two boilers, fired in stages, to supply three areas of a building. One of those areas is sub-divided into three zones. The other two areas are handled by individual zone circulators. The “primary circulator” operates whenever any load circuit is on. All circulators are fixed speed, and there is a partially closed ball valve at the end of the “primary loop.” 

When any one of the three loads circuits is on, there is heat migration into the other two load circuits. The mechanical room where the boilers are located is also very warm, even when only one boiler is firing. Can you spot several errors in this piping layout and propose modifications that would correct them?


Glitch drawing

Are you an ace troubleshooter?

Within the pages of this magazine, PM’s Hydronics Editor John Siegenthaler, P.E., will pose a question to you, our readers, to review a system’s schematic layout and discover its faults, flaws and defects. Discover archived “The Glitch & The Fix” exercises at its radiant-focused website, Good luck!