Navien NFC-175, Installation & Operation Manual

Page: 39 / 124

39 Installing the System Piping
3.7.3 Wiring Diagram - Zone Pump System
NFC boilers can operate a heating system with up to 3 zones. The following is the wiring diagram for a zone pump system with 3 zones.
Without 24VAC Connections
N
A/H
DHW
PRI
L
N
L
N
L
N
L
N
L
Z3
Z2
Z1
AC24VN
AC24VL
lLWCO
R
W
C
T/S_DWH
R
W
C
R
W
C
T/S_CH_ZONE1
T/S_ZONE2
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R W C
NC
NC
COM
NC
NC
COM
LWCO
AC24VL
AC24VN
NC
NC
COM
ZONE1
ZONE2
ZONE3
AC24VN
AC24VL
lLWCO
R
W
C
T/S_Recir.P
R
W
C
R
W
C
T/S_ZONE1
T/S_ZONE2
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R
W
C
Pump Ground
Thermostat 1
Thermostat 2
Thermostat 3
N
A/H
DHW
PRI
L
N
L
N
L
N
L
N
L
Z3
Z2
Z1
Zone pump 1
(max. 2.5 A)
Zone pump 2
(max. 2.5 A)
Zone pump 3
(max. 2.5 A)
Note
●
If you have a 24 V thermostat, connect it to the R & C terminals on the boiler’s PCB.
●
The C terminals are for optional connections with 24 V thermostat COMMON.