Navien NFB Series - Page 37

37Installing the System Piping
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
COM
A/H
DHW PRI
NO NC N L N L N L
COM
A/H DHW PRI
NO
NC N L N L
N
L
COM
NO
NC
ZONE1
COM
NO
NC
ZONE2
COM
NO
NC
ZONE3
AC24VN
SUPPLY RETURN OUTDOOR DHW TANK
AC24VL
LWCO
R
W
C
R
W
C
R
W
C
R
W
C
DHW pump
(max. 2.5 A)
Zone pump 2
(max. 2.5 A)
Zone pump 3
(max. 2.5 A)
Boiler pump
(max. 2.5 A)
LWCO
AC24VL
AC24VN
COM
ZONE3
COM
NC
NC
ZONE3
AC24VN
SUPPLY RETURN OUTDOOR DHW TANK
AC24VL
LWCO
R
W
C
R
W
C
R
W
C
R
W
C
Thermostat 1
DHW Aquastat
(priority)
Thermostat 2
Thermostat 3
Pump Ground
Note
●
The C terminals are for optional connections with 24 V thermostat COMMON.
●
If the DHW Tank is connected to the priority terminal, the T/S Zone 1 input is not available.