Rheem 310 Series Service Instructions Manual page 20

Component Test 4
Warning – 'Live' equipment wear Personal Protective Equipment when
conducting this test.
Sensor Strip Testing: Unplug the sensor strip plug from the control board and using a
multimeter on the kilo-ohms scale, measure between the pins of the sensor strip plug*.
There are six individual tests to be performed as there are six individual sensors contained
along the length of the sensor strip (sensors S0 – S5). As the resistance of each sensor
will change according to its temperature, the resistance measurements for each sensor will
need to be checked against the Temperature/Resistance Table shown below. For this
reason it is best to empty the tank of hot water and then measure the cold water
temperature at the T&PR so a known temperature datum can then be applied to all
sensors which should then in turn all have similar resistance value when tested.
Sensor Test Points
S0 – Between Pins 1 and 9
S1 – Between Pins 2 and 9
S2 – Between Pins 4 and 9
S3 – Between Pins 6 and 9
S4 – Between Pins 3 and 8
S5 – Between Pins 3 and 10
*Note: The sensor strip plug socket test points are quite small, Fine Probe Adapters (part
number WH0020082) can be utilised as probe extensions. Alternatively small pins may be
used however ensure good contact is made when testing.
Sensor Strip Temperature / Resistance Table
T (°C) R (kΩ)
-10 37.45
-9 35.73
-8 34.11
-7 32.56
-6 31.10
-5 29.71
-4 28.39
-3 27.13
-2 25.94
-1 24.81
0 23.73
1 22.71
2 21.73
3 20.81
4 19.92
5 19.09
6 18.29
7 17.52
8 16.80
9 16.11
TM025 Rheem Heat Pump Service Instructions REV: B
Date of Issue: 02/08/07
This document is stored and maintained electronically by
Sensor strip plug
pin configuration
T (°C) R (kΩ) T (°C)
10 15.45
11 14.82
12 14.22
13 13.65
14 13.10
15 12.58
16 12.09
17 11.61
18 11.16
19 10.72
20 10.31
21 9.913
22 9.535
23 9.173
24 8.826
25 8.495
26 8.177
27 7.873
28 7.583
29 7.304
Service. All printed copies not bearing this statement in RED are deemed "uncontrolled".
R (kΩ) T (°C)
30 7.037 50
31 6.782 51
32 6.537 52
33 6.302 53
34 6.076 54
35 5.86 55
36 5.653 56
37 5.454 57
38 5.264 58
39 5.081 59
40 4.905 60
41 4.736 61
42 4.574 62
43 4.418 63
44 4.269 64
45 4.125 65
46 3.987 66
47 3.854 67
48 3.726 68
49 3.603 69
19
Testing the
sensor strip
R (kΩ) T (°C) R (kΩ)
3.485 70 1.853
3.371 71 1.799
3.262 72 1.743
3.157 73 1.695
3.055 74 1.646
2.957 75 1.589
2.863 76 1.552
2.773 77 1.508
2.686 78 1.465
2.602 79 1.424
2.521 80 1.384
2.442 81 1.345
2.367 82 1.307
2.295 83 1.271
2.225 84 1.236
2.157 85 1.202
2.092 86 1.169
2.029 87 1.137
1.968 88 1.107
1.91 89 1.077
8.49