Navien NFC-175 Installation & Operation Manual page 90

Item
2-3. Outdoor Low
Temp Set**
2-4. WWSD Temp
2-5. WWSD On Diff
2-6. Boost Interval
Time***
3. Navien zone cont.
4. SH Control
Method
* A preset or user defined temperature range is set automatically based on
the curve selected. Refer to the settings table for details.
Supply Set
Heat Load
Point Range
1. Finned Tube 120–180°F
Baseboard (48.5–82°C)
140–180°F
2. Fan Coil
(60–82°C)
3. Cast Iron 100–170°F
Baseboard (37.5–76.5°C)
4. Low Mass 80–140°F
Radiant (26.5–60°C)
5. High Mass 80–120°F
Radiant (26.5–48.5°C)
120–170°F
6. Radiators
(48.5–76.5°C)
104–180°F
7. Custom
(40–82°C)
90 Operating the Boiler
Description
Set the maximum temperature for the
Outdoor Reset Control.
Setting range: -4°F (-20°C) – [MAX Set-
●
point – 9°F (5°C)]
Default: 14°F (-10°C)
●
Set the Warm Weather Shut-down
temperature.
Setting range: OFF, 50°F (10°C) –
●
104°F (40°C)
Default: OFF
●
Set the differential temperature to
deactivate the Warm Weather Shut-
down.
Setting range: 0°F (0°C) – 36°F (20°C)
●
Default: 5°F (3°C)
●
Set the boost interval time.
Setting range: 0 – 120 min
●
Default: 0 min
●
Enable or disable heating zones utilizing
the Navien Zone Controller.
Setting range: Enabled/Disabled
●
Default: Disabled
●
Select a heating control type.
1: Supply Temperature
2: Return Temperature
3: Sys Supply Temperature
4: Sys Return Temperature
Default: Supply Temperature
●
Return Set
Point Range
101–147°F
(38–63.5°C)
116–147°F
(46.5–63.5°C)
86–139°F
(30–59°C)
70–116°F
(21–46.5°C)
70–101°F
(21–38°C)
101–139°F
(38–59°C)
86–149°F
(30–65°C)
Heat loads 1-6 show the preset temperature ranges based on the load
type selected, while heat load 7 provides a custom temperature range.
When the custom temperature range is in use, the boiler operates based
on the user–defined "Absolute Min" and Absolute Max" temperature
settings.
** Available only when "2. Outdoor Reset ON/OFF" is set to "Enabled".
*** The boost interval time may be set to prevent interruption in space
heating while using the Outdoor Reset Control mode, due to changes
in heat load conditions. With the boost interval time enabled, the boiler
increases the space heating supply temperature by 9°F (5°C) and the
return temperature by 5°F (3°C) after a set time elapses.
CAUTION
An outdoor sensor error may occur if the Outdoor Reset
Control mode is enabled without the outdoor sensor installed
Note
11.3.4 Setting the DHW Operation
To set the boiler's DHW operation, press the Menu button
( ), and then select "4. DHW Operation".
Remarks
Default
Rotate the Command dial (
to increase/decrease setting values. Press the Command dial (
to select an item or to confirm after making changes.
User-
defined
In the Outdoor Reset Control mode, the boiler's water
temperature is regulated according to the outdoor
temperature to maximize boiler efficiency and reduce
energy usage. This mode must remain enabled and
the outdoor sensor must be installed to comply with
federal efficiency regulations. The Outdoor Reset mode
cannot be used when using the DHW mode.
) to switch between the list items or
)