Tee’d Off

One Chance to Get It Right

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.

Can you spot several details that will lead to problems? How would you design the system differently?

An unpressurized outdoor wood-fired heater is installed to supply heat to fin-tube baseboard install in a two-story home.

Assuming that the aquastat is operating correctly, and that essential details are all present and correctly installed, why is the system behaving this way?

Can you identify several errors or suggest some more refined design approaches for this system?

An installer decides to use a buffer tank between a mod/con boiler and a highly zoned distribution system. 

An installer is asked to provide a multi-zone floor heating system supplied from a single-stage non-modulating geothermal heat pump.

An installer pipes up a two-zone, low-temperature radiant floor heating system to a conventional gas-fired boiler, as shown below.