Navien NCB-20LHWE Installation & Operation Manual page 51

Setting the Pump Overrun Time
Display
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 o . 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
This menu is used to con gure the desired DHW capacity. When
the boiler operates in the Normal mode, the max DHW capacity
is limited to the set value (%).
DHW Max Heat Capacity Setting Range
Range
[DHW Min Heat Capacity set
point + 20%] – 100%
Setting the DHW Min Heat Capacity
Display
This menu is used to con gure the desired DHW capacity. When
the boiler operates in the Normal mode, the min DHW capacity
is limited to the set value (%).
DHW Min Heat Capacity Setting Range
Range
DHW Min Heat Capacity –
[DHW Max Heat Capacity set
point - 20%]
Description
Pump overrun time (min)
Description
DHW max heat capacity (%)
Remarks
Default: 100%
Description
DHW min heat capacity (%)
Remarks
Default: DHW Min Heat
Capacity (%)
Setting the DHW Wait Time
Display
The DHW wait time is the duration that the boiler maintains the
DHW supply mode after a DHW demand. With the DHW wait
time enabled, a faster DHW supply may be available when there
is a subsequent DHW demand. The boiler switches the 3-way
valve to space heating mode when the set time elapses.
Default: 5 minutes
Range: 0–20 minutes
When a call for space heating occurs simultaneously
Note
with a DHW demand, the 3-way valve will
immediately switch to space heating mode at the end
of the DHW demand.
Setting the Burner-O Temperature
Display
During space heating, the boiler turns o the burner when the
space heating supply temperature meets or exceeds the burner-
o temperature.
Burner-O Temperature Range
Range
0–30°C
Description
DHW wait time (min)
Description
Burner-o temperature (°C)
Remarks
Default: 2°C
Operating the Boiler 51