Navien NFB-175 Mode D'emploi page 37

3.6.4 Wiring Diagram - Zone Pump System with DHW Tank
The NFB Boilers can operate a heating system with up to 2 zones and 1 DHW Tank. The following is the wiring diagram for a zone pump system
with 2 zones and 1 DHW Tank.
Without 24VAC connections
Boiler pump
(max. 2.5 A)
DHW pump
(max. 2.5 A)
Zone pump 2
(max. 2.5 A)
Zone pump 3
(max. 2.5 A)
The C terminals are for optional connections with 24 V thermostat COMMON.
Note
●
If the DHW Tank is connected to the priority terminal, the T/S Zone 1 input is not available.
●
SUPPLY RETURN OUTDOOR
Pump Ground
NC
COM
NC
LWCO
COM
AC24VL
LWCO
AC24VN
AC24VL
AC24VN
NC
NO
COM
NC
NO
COM
NC
NO
COM
LWCO
AC24VL
AC24VN
C
W
R
C
W
R
C
W
R
C
W
SUPPLY RETURN OUTDOOR DHW TANK
R
DHW TANK
C
W
R
DHW Aquastat
(priority)
C
W
R
Thermostat 1
C
W
R
Thermostat 2
C
W
R
Thermostat 3
Installing the System Piping 37