Navien NFC-175 Installation & Operation Manual page 68

3. On the sub NPE water heater panel, press and hold the
Diagnostic and Down(-) buttons for more than 2 seconds.
"SL.01" will appear on the display to confirm that this water
heater is set as a sub.
4. Repeat step 2 to configure the rest of the sub NPE water
heaters in the system.
5. On the main NFC boiler panel, press the Command dial (
button when the following screen appears. All the display
screens on the configured water heaters will return to the
temperature display.
To add additional sub water heater at a later time,
Note
●
repeat step 2.
To cancel the cascade communication settings, on
●
the main NFC boiler panel, press the Back button
( ) and the Menu button (
for 3 seconds, and then select "4. Cascade Status
and Set". Then, select "2. Cascade System Removal"
and select "YES". The water heaters will revert to
independent operation. To reassign the main NFC
boiler, repeat steps 1-4.
68 Installing a Cascade System
)
) simultaneously