Navien NHB Series, Installation & Operation Manual

Page: 95 / 135

95 Operating the Boiler
11.5.3 Setting the DHW Operation (Indirect)
To set the boiler’s indirect DHW operation, tap the Control button
(
) > DHW Control on the screen.
Tap an item to set the DHW operation settings.
Item Description
1. DHW Demand
Select a device for sensing the DHW
demand.
1. Aquastat
2. Tank Sensor
Ɣ
Default: Aquastat
2. DHW Control
Method
Select a DHW control type.
1. Supply
2. System Supply
Ɣ Default: Supply
3. Anti Legionella*
function
Enable or disable the protection against
legionella bacteria.
Ɣ
Setting range: ON/OFF
Ɣ
Default: OFF
4. DHW Tank Set
Temp
Set the DHW tank target temperature.
Ɣ
Setting range: 86°F (30°C) – 149°F
(65°C)
Ɣ
Default: 122°F (50°C)
5. DHW Boiler Set
Temp
Set the DHW boiler target temperature.
The setting range varies depending on
the DHW demand types.
Ɣ
When an aquastat is used, the
setting rage is same as the DHW
temperature setting range.
Ɣ
When a tank sensor is used:
-
[DHW Tanks Set Temp + 18°F
(10°C)] – 194°F (90°C)
- Default: 180°F (82°C)
6. DHW Priority time
Set the DHW priority time.
Ɣ
Setting range: 0 – 180 min
Ɣ
Default: 30 min
Item Description
4. Curve select
Select the outdoor reset load.
Ɣ
Default: Finned Tube Baseboard
5. WWSD
Temperature
Enable or disable the Warm Weather
Shut Down temperature function.
Ɣ
Setting range: OFF, 50°F (10°C) –
104°F (40°C)
Ɣ
Default: OFF
Note
If the outdoor reset
temperature exceeds the
set temperature, all SH
demands are ignored.
6. WWSD On
Differential
Enable or disable the Warm Weather
Shut Down On Differential temperature
function.
Note
If the outdoor reset
temperature is lower
than the set temperature,
this feature is enabled
depending on SH demands.
7. Boost Interval Time
Set the boost interval set time (min).
Ɣ
Setting range: 0 – 120 min
Ɣ
Default: 0 min
Note
To change the set temperature range (Y-axis in the
graph), tap the Set button (
) > Parameter on the
screen, and then adjust the values for the Supply/
Return absolute Min/Max point items. For more
information about detailed settings, refer to “11.6.3
Setting the Operation Parameters.”