Navien NFB Series User Manual

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.

Navien NFB Series Specifications

General

Type	Condensing Boiler
Fuel Type	Natural Gas or Propane
Heat Exchanger	Stainless Steel
Vent Type	Direct Vent
Vent Diameter	2" or 3"