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55
Installing the System Piping
3.7.10 Wiring Diagram - Optional Supply/Return Temperature Sensors
SUPPLY
TEMPERATURE SENSOR
RETURN
OUTDOOR
T/S_ZONE3
R
W
C
T/S_ZONE2
R
W
C
T/S_ZONE1
R
W
C
AC24VN
AC24VL
lLWCO
R
W
C
T/S_Recir
Temperature
Sensor
Thermal insulation
Return Temperature Sensor (optional)
Supply
Temperature Sensor
(recommended)
<NFC-H>
Cable tie
Note
●
To control the boiler supply or return water temperature using the external temperature sensor,
configure the system accordingly. On the front panel, press the Menu button (
) to enter the
setting menu, and then select 2. Space Htg Operation > 5. SH Control Method to select one of the
control modes.
●
For best performance, wrap the sensor and pipe section with thermal insulation.
●
A single temperature sensor is supplied with the boiler. Additional temperature sensors are
available for purchase. Contact Navien for more information.
Summary of Contents for NFC-250/175H
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