Navien NPE-180A Installation Manual page 39

2. On the slave water heater, 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 slave.
3. Repeat step 2 to configure the rest of the slave water heaters in
the system.
4. On the master water heater, press and hold the Diagnostic
and Up(+) buttons for more than 5 seconds. All the display
screens on the configured water heaters will return to the
temperature display.
To add additional slaves at a later time, repeat step
Note
2.
To cancel the cascading communication setup,
on the master water heater, press and hold
the Diagnostic and Reset buttons for more
than 5 seconds. The water heaters will revert
to independent operation. Repeat steps 1-4 to
reassign the master water heater.
38 Installing a Cascading System