Navien NCB-180, Service Manual

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58 NCB Service Manual Version 1.0
Point Function CN No. Wire Color Normal Value Check
A
DHW Inlet Temperature
Sensor
CN13
1-2
BLUE-BLUE DC 0~5V
Voltage changes according to
temperature.
HEATING Return
Temperature Sensor
CN13
3-4
BLUE-BLUE DC 0~5V
Voltage changes according to
temperature.
DHW outlet Temperature
Sensor
CN13
5-6
RED-RED
(BLUE-BLUE)
DC 0~5V
Voltage changes according to
temperature.
HEATING Supply
Temperature Sensor
CN13
7-8
BLUE-BLUE DC 0~5V
Voltage changes according to
temperature.
Exhaust Sensor
CN13
9-10
BLUE-BLUE DC 0~5V
Voltage changes according to
temperature.
High Temperature Limit
Switch
CN13
11-12
BLACK-BLACK DC 0V Normally Shorted. Confirm RMS voltage.
B Outdoor sensor CN11 - DC 0~5V
Voltage changes according to
temperature.
C Flow Sensor
CN5
1-3
RED-BLACK DC 12V Confirm steady voltage.
CN5
2-3
WHITE-BLACK PULSE Check Pulse.
D Water Pressure Sensor
CN22
1-2-3
RED-
YELLOW(GREEN)-
BLACK
E APS
CN6
1-2
RED-BLACK DC 5V Confirm steady voltage.
CN6
1-4
WHITE-BLACK DC 0.3~4.5V
Voltage changes according to the APS
operation.
F
Flame Rod
CN2
1
BLACK DC 10uA
Measure the current when the burner is
operating.
Ground Wire
CN2
2
GREEN-YELLOW Check for properly grounded wire.
G Gas Valve
CN16
1-2
RED-YELLOW DC 22~24V
Confirm voltage as the Main Gas Valve 1
is operating.
CN16
1-3
WHITE-RED DC 22~24V
Confirm voltage as the Main Gas Valve 2
is operating.
H Dual Venturi
CN15
1-4
BROWN-WHITE
ON : AC 95~120V
OFF : 0V
Confirm voltage relative to operation.
CN15
4-5
BLUE-WHITE
ON : AC 95~120V
OFF : 0V
I 3-Way Valve
CN14
1-2-3
BLACK-RED-
BROWN
AC 97~138V