Navien NPE Installation & Operation Manual page 26

External Recirculation Mode
To use the external recirculation mode:
1. Connect the water supply to support recirculation. Refer to the
"[NPE-180A/ 210A/ 240A]" diagram on page 24.
2. Set the 2-way valve inside the water heater to "EXT. "
3. Set the front panel DIP switches at the far left (set of ten) to:
1—OFF; 2—ON.
ON
1 2 3
The following diagram shows the external recirculation flow for
pre-heating:
26 Installing the Water Heater
ON
4 5 6 7 8 9 10
Primary Heat Exchanger
Buffer
Secondary Heat Exchanger
Tank
Circulation
2-Way
Pump
Valve
Closed
Hot
Recirculation
Water
Water Supply
Supply
External Recirculation Mode
Flow
Sensor
Check
Valve
Water
Adjustment
Valve
Domestic
Water
Supply