Check Whether The Thermistor - Cold Water Is Normal - Noritz NR501-OD Service Manual

A

Check whether the Thermistor - Cold Water is normal.

Normal
Check that actual water temperature
and maintenance monitor #30 match.
When not using the maintenance monitor:
Thermistor-Cold Water converted from the
resistance between CN63 White 4 - Black 2
(refer to the thermistor temperature
characteristics below) and the actually
measured water temperature should be
about the same.
When measuring the resistance,
disconnect the connector and check
the male side.
Abnormal
Circuit Board
14
13
12 BL
11 W
10 R
14
9 Y
8
Main
13
7
Circuit
6 BK
12 BL
5 BK
Board
4 W
11
W 3 W
2 BK
10 R 1 W
<CN63>
1 2 3
9 Y
<CN135>
8
7
<CN142>
<CN78>
6
BK
2
1
5 BK
1 BL 2
3 BL
4 W 4 R
5 W
<CN101>
6 O
3 W
7
GY
8
BK <CN10>
2 BK
9
10 W
1 W
<CN89B>
11 BL
12
6 BK 13 W
5 R 14
<CN63>
15 BL
4
3
2 W
1 W
<CN42> <CN89A>
34
12 W
11 Y
10 O
9 R
8
7
6 BK
5 V
4 G
3 O
2 Y
1 W
<CN59>
1
2
3 4 3 2 1
4 BL
4 R
3 BL BR Y BL R
5 O
2 BL
6 Y <CN27>
1 R
7 W
Power
<CN104>
Circuit
3 R
Board
2 BL
1 G
3
2
1
<CN75>
3 2 1
BL/W R/R G
<CN102>
Ch eck for improper connection of wiring.
Replace the Thermistor - Cold Water.
Replace the Circuit Board set.
* It is not necessary to replace the
Display Window Circuit Board.
Display Window
Fuse
Circuit Board
Data
Display
W 3 1 W
BK 4 2 BK
<CN92>
Dip Switch
1 2 3 4
R BL BL BL
<CN142>