Navien NPE-32AWE Installation Manual page 40

2. On the slave water heater, press and hold the Diagnostic
and Down
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
screens on the configured water heaters will return to the
temperature display.
To add additional slaves at a later time, repeat
Note
step 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.
40 Installing a Cascading System