Thermistor - Heat Exchanger Abnormality; Thermistor - Exhaust Abnormality - Noritz NR501-OD Service Manual

Error Codes
Display Remote
Window Controller
331 (Open)
33

Thermistor - Heat Exchanger abnormality

332 (Short)
Chec k the Ther mistor - Heat Exchanger open or short circuit.
Normal
CN63 : Between White 3 - Black 2
DC 1 - 4.5V
Resistance : Refer to the table below.
When measuring the resistance,
disconnect the connector and
check the male side.
Error Codes
Display Remote
Window Controller
351, 353 (*1)
35

Thermistor - Exhaust abnormality

352, 354 (*2)
Check the Thermistor - Exhaust open or short circuit .
Normal
CN63 : Between Black 6 - Black 2
Refer to the thermistor temperature
characteristics below .
When measuring the resistance,
disconnect the connector and
check the male side.
Description
Abnormal
Circuit Board
14
14
13
13
12
BL
11 W
12 BL
10 R
9 Y
8
11 W Main
7
6 BK Circuit
10 R 5 BK
Board
4 W
3 W
9
Y
2 BK
1 W
8
<CN63>
1 2 3
<CN135>
7
6
BK
<CN78>
5 BK
2
1
1 BL 2
4 W
3 BL
4 R
3 W
5
W
6 O
7 GY
2 BK
8 BK <CN10>
9
1 W 10 W
<CN89B>
11
BL
12
6 BK 13 W
5 R 14
<CN63> 15 BL
4
3
2 W
1 W
<CN42>
<CN89A>
Description
The detail about (*1) and (*2)
Abnormal
Circuit Board
14
14
13
13
12 BL
11 W
12
BL
10 R
9 Y
8
11 W Main
7
6 BK Circuit
10 R 5 BK
Board
4 W
3 W
9 Y
2
BK
1 W
8
<CN63>
1 2 3
<CN135>
7
6 BK
<CN78>
5 BK
2
1
1
4 BL 2
W
3 BL
4 R
3 W
5 W
6
O
7 GY
2 BK
8 BK <CN10>
9
1 W
10 W
<CN89B>
11 BL
12
6 BK
13 W
5 R 14
<CN63> 15 BL
4
3
2 W
1 W
<CN42>
<CN89A>
44
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 <CN27>
Y
1 R
7 W
<CN142>
Po wer
<CN104>
Circuit
3 R
Board
2 BL
1 G
<CN101>
3
2
1
<CN75>
3 2 1
BL/W R/R G
<CN102>
Check for improper connection of wiring.
Replace the Thermistor - Heat Exchanger.
Replace the Circuit Board set.
* It is not necessary to replace the
Display Window Circuit Board.
DV model only
During combustion
Thermistor
Open
353
354
Short
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
4 3 2 1
3
4 BL
4 R
3 BL BR Y BL R
5 O
2 BL
6 Y <CN27>
1 R
7 W
<CN142>
Po wer
<CN104>
Circuit
3 R
Board
2
BL
1 G
<CN101>
3
2
1
<CN75>
3 2 1
BL/W R/R G
<CN102>
Check for improper connection of wiring.
Replace the Thermistor - Exhaust.
Replace the Circuit Board set.
* It is not necessary to replace the
Display Window Circuit Board.
Displ ay 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>
Except during combustion
351
352
Displ ay 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>