94
Issue 2 14/07/16
10 Appendix
10.5.2 Sensor resistance testing
Upper Sensor
1. Determine resistance value of upper sensor. Test across
grey wires.
2. Draw quart of water off
T&P valve
. Using a thermometer,
determine water temperature.
3. Use table below to verify correct resistance per water
temperature measured.
Lower Sensor:
1. Determine resistance value of lower sensor. Test across
center wire (common) to each outside wire. Resistance of
both thermistors in the lower sensor should be close to each
other. If the resistance values for both thermistors are not
close to each other, replace the lower sensor. The dual
thermistors are used to provide high limit protection in case
the thermostat circuit fails to shut off the water heater.
2. Draw quart of water off
Drain Valve
. Using a thermometer,
determine water temperature.
3. Use table below to verify correct resistance per water
temperature measured.
10.5.3 Sensor resistance at various temperatures
Example: If water temperature is 26.7°C, then the resistance
through the sensor would be 8449 (see shaded area).
In Degrees C
°C
0
1
2
3
4
5
6
7
8
9
4.5
26109
25400
24712
24045
23399
22771
22163
21573
21000
20445
10
19906
19383
18876
18383
17905
17440
16990
16553
16128
15715
15.5
15314
14925
14548
14180
13823
13477
13140
12812
12494
12185
21.1
11884
11592
11308
11032
10763
10502
10248
1000
9760
9526
26.7
9299
9078
8862
8653
8449
8250
8057
7869
7685
7507
32
7333
7165
7000
6839
6683
6531
6383
6238
6098
5961
37
5827
5697
5570
5446
5326
5208
5094
4982
4873
4767
44
4663
4562
4464
4368
4274
4183
4094
4006
3922
3839
49
3758
3679
3602
3527
3453
3382
3312
3244
3177
3112
55
3048
2986
2925
2866
2808
2752
2697
2643
2590
2538
60
2488
2439
2391
2344
2298
2253
2209
2166
2124
2083
65.5
2043
2004
1966
1928
1891
1856
1820
1786
1753
1720
71
1688
1656
1625
1595
1566
1537
1509
1481
1454
1427
76
1402
1376
1351
1327
1303
1280
1257
1235
1213
1191
82
1170
1150
1129
1110
1090
1071
1053
1035
1017
999
88
982
965
949
933
917
901
886
871
857
842
93
828
814
801
788
775
762
749
737
725
713
Caution
Be Careful When Making Resistance Measurements Not
to Damage or Deform Connectors or Connector Pins.
Note
Sensor resistance increases as the temperature falls.
Are readings correct
Replace thermistor
Check harness
continuity.
continuity okay?
Replace control board
Replace harness
No
No
Yes
Yes
Upper thermistor
location (applicable
models)
Lower thermistor
access located
inside control box.
Fig. 85
Содержание 24/39
Страница 1: ......
Страница 65: ...Issue 2 14 07 16 65 Parts List and Illustrations 9 9 10 HIflo models 62 341 and 54 418 440 Natural Gas Fig 34 ...
Страница 69: ...Issue 2 14 07 16 69 Parts List and Illustrations 9 9 15 HIflo LPG models L62 309 L54 399 Fig 31 ...
Страница 112: ...112 Issue 2 14 07 16 ...
Страница 113: ...Issue 2 14 07 16 113 ...
Страница 114: ...114 Issue 2 14 07 16 ...