Navien NHB-055 Installation & Operation Manual page 81

Setting the Pump Overrun Time
Display
Pump overrun time (min)
S R O/R psi
The pump overrun time is the duration the circulation pump
continues to run between the space heating supply or return
temperature reaching the set point and the burner turning off. If
the space heating supply or return temperature remains outside of
the boiler operation temperature range for a set period, the pump
stops for 10 mins, runs again for 5 mins, and then repeats the cycle.
Default: 40 minutes
Range: 3–40 minutes
Setting the DHW Max Heat Capacity
Display
DHW Max heat capacity (%)
S R O/R psi
This menu is used to configure the desired DHW capacity. When
the boiler operates in Normal mode, the DHW capacity is limited to
the set value (%).
Default: 100%
Range: [DHW Min heat capacity + 20%]–100%
Setting the Burner-Off Temperature Differential
Display
Burner-off temperature (°F)
S
R O/R psi
During space heating, the boiler turns off the burner when the
space heating supply temperature meets or exceeds the burner-off
temperature.
Burner-Off Temperature Range
Range
2–54°F (1–30°C)
Description
Description
Description
Remarks
Default: 4°F (2°C)
Setting the Burner-On Temperature Differential
Display
Burner-on temperature (°F)
S R O/R psi
During space heating, the boiler turns on the burner when
the space heating supply temperature is below the burner-on
temperature.
Burner-On Temperature Range
Range
2–54°F (1–30°C)
Setting the Supply Absolute MAX Temperature
Display
Supply absolute MAX set point (°F)
S R O/R psi
This menu can be used to change the maximum supply
temperature range in Supply Control mode. When Custom mode is
configured in Outdoor Reset Control mode, changes to the supply
temperature are based on the supply absolute MAX temperature
range.
Supply Absolute MAX Temperature Range
Range
[MIN set point +
36°F (20°C)] – 194°F (90°C)
Description
Remarks
Default: 5°F (3°C)
Description
Remarks
Default: 180°F (82°C)
Operating the Boiler 81