Navien NFC-175, Service Manual

Page: 39 / 138

NFC Service Manual 39 Version 1.0
Combi Pre-Heat
When using the combi pre-heat feature, you can choose
commands in the menu to preheat according to the set DHW
temperature.
Item Description
1. Always on
Set to repeat DHW Recirculation
(default).
2. Intelligent*
Set to detect DHW usage for a week
and repeat the detected cycle.
3. Weekly*
The user can choose commands for
DHW Recirculation on a weekly basis.
1. 1 Day: schedule a command for the
week.
2. 3 Day: schedule commands for
Weekdays, Saturdays, and Sundays.
3. 7 Day: schedule commands for each
day of the week.
* To choose this option you must set up the Time settings in the
Configuration menu.
Note
If there is a SH Demand signal during combi pre-heat,
the space heating will take priority.
Press the Back button ( ) to return to the previous screen or menu.
Item Description
1. DHW Set Temp
Set the hot water temperature(°F).
●
Setting range: 86 - 140°F (30 - 60°C)
●
Default: 122°F (50°C)
2. DHW Recirculation
When only one NFC boiler is connected:
Set the Recirculation type and Schedule
settings (if there is only one boiler).
●
Recirculation type
-
No Recirculation
-
Combi Pre-Heat
-
External
Note
Depending on the
recirculation type, you can
select combi pre-heat or
external recirculation.
When the cascade system is installed:
Set the Recirculation On/Off,
Recirculation type, and Schedule
settings.
●
Recirculation On/Off (Default: ON (Use))
- OFF (Not in Use): Recirculation
-
ON (Use): Recirculation
●
Recirculation type (Default: Always On)
-
Always On
-
Weekly
-
Aquastat
-
Manual
Note
You can only select external
recirculation when using the
Cascade system.
When installing only one NFC boiler, refer to “3.6.4 System
Application - Air Handler System” and Chapters 3.6.6, 3.6.7 in
the Installation & Operation Manual on connecting system
applications.