10
Installing the Device
System Diagram for NPN
WARNING
A mixing valve must be installed in the system in order to limit the DHW output
temperature and prevent scalding. Setting the mixing valve to 115–120
℉
is
recommended.
Install a spring check valve for vertical pipe runs. Do not use a swing check
valve with vertical piping.
Install either a spring check valve or a swing check valve in a horizontal pipe
run.
An outdoor sensor and a flow switch are supplied with the product.
Use 18 AWG cables for thermostat wiring.
When using an external pump, connect the pump to the water heater PCB
directly using a Navien External Pump Cable (GXXX001319).
Note
