Navien NHB-055 Installation & Operation Manual page 60

Setting the Heat Load for the Outdoor Reset Control Mode
Display
S R O/R
Pri psi
S R O/R
psi
Pri
This mode is used to configure the heat load type to be used with
the Outdoor Reset Control mode.
A preset or user-defined temperature range is selected
automatically based on the heat load type selected.
Types of Heat Load
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)
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.
60 Operating the Boiler
Description
Outdoor Reset heat load types
1: Finned tube baseboard
2: FAN coil
3: Cast iron baseboard
4: Low mass radiant
5: High mass radiant
6: Radiator
7: Custom
Outdoor Reset heat load not
selected
Return Set
Remarks
Point Range
101–147°F
Default
(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 User-
(30–65°C) defined
Setting the Lowest Outdoor Temperature
Display
Lowest outdoor temperature (°F)
S
R O/R
Pri psi
Lowest outdoor temperature not
in use
S R O/R
Pri psi
This mode is used to configure the lowest outdoor temperature.
The boiler will operate at the high end of the supply or return set
point range at this outdoor temperature.
Outdoor Low Temperature Setting Range
Range
-4°F (-20°C) – [Outdoor High
Temperature set point - 9°F
(5°C)]
Setting the Highest Outdoor Temperature
Display
Highest outdoor temperature (°F)
S R O/R
psi
Pri
Highest outdoor temperature not
in use
S
R O/R
Pri psi
This mode is used to configure the highest outdoor temperature.
The boiler will operate at the low end of the supply or return set
point range at this outdoor temperature.
Outdoor High Temperature Setting Range
Range
[Outdoor Low Temperature set
point + 9°F (5°C)] – 104°F (40°C)
Description
Remarks
Default: 14°F (-10°C)
Description
Remarks
Default: 70°F (21°C)