Navien NHB-055 Installation & Operation Manual page 27

3.5.2 System Application - Zone System with Zone Valves
Make-up Water
Backflow preventer
Pressure reducing valve
Expansion Tank
System application drawings are intended to explain the system piping concept only.
Note
Install a filter in the system return to remove foreign objects from the system. Foreign objects inside the system may result in
abnormal system operation.
Refer to "3.3 Filling the System" on page 24 for make-up water connections and refer to the requirements of your local codes
to ensure compliance.
Use a pump with an integral check valve or install a check valve at the pump outlet.
Refer to "3.6.4 Wiring Diagram - Generic Zone System with Zone Valves" on page 33 for wiring connections.
Zone #2
Zone #1
System Pump
Air Separator
Additional Zone
Zone Valve
(Typical)
Not to exceed 4 pipe Dia or Max. 12"
Boiler Pump
Return filter
Installing the System Piping 27