Navien NPE-180A2 Installation Manual page 29

External Recirculation Mode
To use the external recirculation mode:
1. Connect the water supply to support
recirculation. Refer to the "[NPE-180A2/ 210A2/
240A2]" diagram on page 26.
2. Set the 2-way valve inside the water heater to
"EXT. "
3. Press the Menu button (
menu and select 1. Recirculation Setting >
2. External Recirculation by pressing the OK
button ( ).
) to access the Main
For more information about the
Note
●
Recirculation settings, refer to
"Included Items" on page 79.
If the A2-type model requires
●
an external pump, follow the
instructions in "3.4.3 External Pump
Wire Connection" on page 30
first and select YES on the screen
asking whether the external pump is
connected to the PCB.
Model Step 1 Step 2
A2-
type
S2-
type
The following diagram shows the external
recirculation flow for pre-heating:
Primary Heat Exchanger
Buffer
Secondary Heat Exchanger
Tank
2-Way
Valve
Closed
Check Valve
Hot
Recirculation
Water
Water Supply
Supply
[External Recirculation Mode using the Recirculation Inlet]
Step 3
Always On
Use Ext.
Intelligent
Ext.
Pump
Recirc
Weekly
Yes/No
HotButton
Always On N/A
Intelligent N/A
Ext.
Schedule
Recirc
Weekly
Set
HotButton N/A
Flow
Sensor
Circulation Pump
Water
Adjustment
Valve
Domestic
Water
Supply
Installing the Water Heater 29