Navien NFB-175H, Installation Manual, Page: 46 / 135

46 Installing the System Piping
When connecting the DHW Tank Sensor
The Navien Universal Temperature sensor can be used as a DHW Tank Sensor. When installing the Universal
Temperature sensor to the boiler, follow these guidelines:
●
This sensor is compatible for use with aquastat immersion wells. Attach an aquastat immersion well to the
DHW tank before installing the sensor.
●
When installing the sensor to the tank, verify that the sensor is completely inserted into the immersion well.
●
Install the included clip on the groove on the immersion well as shown in the illustration.
●
Insert the wire through the available eyelet on the clip then wrap it around the clip once to fix the sensor to
the well.
●
Complete the installation by connecting the wires to the DHW Tank terminals located on the PCB.
Note
When inserting the sensor into the immersion well, heat conductive paste can be used to improve
thermal transfer between the two components.
Installing the DHW Tank Sensor
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
COM
A/H
DHW
PRI
NO
NC
N
L
N
L
N
L
COM
NO
NC
N
L
N
L
N
L
Pump Ground
COM
NC
ZONE3
AC24VN
SUPPLY RETURN OUTDOOR DHW TANK
AC24VL
LWCO
R
W
C
R
W
C
R
W
C
R
W
C
<NFB-H>
System
Pump
(max. 2.5 A)
Boiler
Pump
(max. 2.5 A)
DHW Pump
(max. 2.5 A)
WARNING
Use only the Navien Universal Temperature sensor (#GXXX001769). The use of other sensors may result in
higher water temperatures than expected.