IBC Sl Series Installation & Operating Manual page 58

Air handler
Domestic water, hot and cold: A thermostatic tempering valve may be required by
local code.
Indirect hot water tank
Figure 44 Two pump, two load parallel piping concept
3.11.2.3 Multiple-boiler piping
Multiple IBC boilers can be installed in a single heating system to provide redundancy,
increased output, and greater heating plant turn-down capabilities. Primary-secondary piping
must be employed, and each boiler must be installed with its own pump as illustrated below.
This approach provides constant head and flow at each boiler, regardless of flow variations in
the main building loop.
54
Section: Installation