Navien NFB-175H, Installation Manual, Page: 109 / 135

109 Operating the Boiler
Item Description
19. Sys pump
Oper(DHW)
Turn on or turn off the
system pump in DHW
mode.
●
Setting range: On/Off
●
Default: Off
20. Zone2 pump
Oper(DHW)
Turn on or turn off Zone 2
pump in DHW mode.
●
Setting range: On/Off
●
Default: Off
21. DHW pump
Oper(DHW pri)
Turn on or turn off the
DHW pump in DHW
mode when both the
space heating and DHW
demands are present.
●
Setting range: On/Off
●
Default: On
22. Boiler Pump
Delay**
Set the space heating
pump over-run time.
●
Setting range: 3 – 40
min
●
Default: 40 min
23. DHW Demand
On Diff
When the DHW
temperature sensor is
used:
●
Setting range: 0–10°C
(0–18°F)
●
Default: 3°C (5°F)
24. DHW Demand
Off Diff
When the DHW
temperature sensor is
used:
●
Setting range: 0–5°C
(0–9°F)
●
Default: 0°C (0°F)
25. Service Notif
Time
Set the time for service
notification.
●
Setting range: 30 –
3650 days (10 years)
●
It can be set in 10 day
increments.
●
Default: 1820 days (5
years)
Item Description
12. Anti Fast Cycling
Time*
Set the anti-fast cycling
time.
●
Setting range: 0 – 20 min
●
Default: 3 min
13. DHW Min Limit
Set the DHW minimum
heat capacity.
●
Setting range: DHW
minimum capacity (%)
– [DHW MAX capacity
limit - 20] %
●
Default: Boiler’s
minimum heat capacity
14. DHW Max Limit
Set the DHW maximum
heat capacity.
●
Setting range: [DHW
Min capacity limit + 20]
% – 100%
●
Default: 100%
15. Freeze
protection
Set the pump freeze
protection temperature.
●
Setting range: 43°F
(6°C) – 50°F (10°C)
●
Default: 50°F (10°C)
Note
The boiler pump
will operate to
provide system
freeze protection
when the water
temperature falls
below this value.
16. Low Sys Pressure
Set the low water system
pressure.
●
Setting range: 4 – 17 psi
●
Default: 6 psi
17. High Sys
Pressure
Set the high water system
pressure.
●
Setting range: 40 – 80
psi
●
Default: 50 psi
18. Boiler pump
Oper(DHW)
Turn on or turn off the
boiler pump in DHW
mode.
●
Setting range: On/Off
●
Default: Off