Version 1.4
62 NCB-E Service Manual
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
RED-BLACK
DC 0-5V
Voltage changes according to the Water
Pressure.
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
J
Power Input
CN1
1-2
WHITE-BLACK
AC 97-138V
Confirm appropriate power source.
Confirm the FUSE.
Confirm the circuit breaker.
K
Igniter
CN17
1-2
BLUE-BLUE
ON : AC 97-138V
OFF : 0V
Confirm voltage when the unit is igniting.
L
Pump
CN18
1-3
YELLOW-WHITE
ON : AC 96-138V
OFF : 0V
Confirm voltage as operating.