Navien NPE-240A Installation Manual

Installing a Cascading System 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.
Note

To add additional slaves at a later time, repeat 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.

Navien NPE-240A Specifications

General

Type	Tankless
Fuel Type	Natural Gas or Propane
Energy Factor	0.97
Energy Efficiency	97%
Voltage	120V
Ignition Type	Electronic
Maximum Input	199, 900 BTU/h
Water Connection Size	3/4"
Gas Connection Size	3/4"
Warranty	15-year on heat exchangers, 5-year on parts, 1-year on labor
Dimensions	17.3" W x 13.2" D x 27.4" H