Electronic Components; Temperature Sensors - IBC SL 14-115 G3 Installation And Operating Instructions Manual

5-2
SL 14-115 G3, SL 20-160 G3, SL 30-199 G3 MODULATING GAS BOILERS

5.2 ELECTRONIC COMPONENTS

This section details the method for troubleshooting the non-standard electronic
components on the boiler including the electronic differential air pressure sensor and the

temperature sensors.

5.2.1 Temperature Sensors
The resistance of the temperature sensors varies inversely with temperature. To test,
measure the temperature of the sensed environment and compare with the value derived
from the measurement of the resistance (obtained by connecting a good quality test meter
capable of measuring up to 5,000 kΩ (5,000,000Ω) at the controller end of the sensor
lead).
To obtain a resistance reading, remove power to the boiler. For the supply water and
return water temperature sensors, remove the wire leads by disconnecting their respective
Molex connectors. Place multi-meter probes into the sensor's female Molex connector
socket. Do not apply voltage to the sensor as damage may result.
TEMPERATURE RESISTANCE
°F °C
0 -18
5 -15
10 -12
15 -9
20 -7
25 -4
30 -1
35 2
40 4
45 7
50 10
55 13
60 16
65 18
70 21
75 24
80 27
85 29
90 32
95 35
Table 9: Temperature Sensor resistance values
TEMPERATURE
Ω °F
85,362 100
72,918 105
62,465 110
53,658 115
42,218 120
39,913 125
34,558 130
29,996 135
26,099 140
22,763 145
19,900 150
17,436 155
15,311 160
13,474 165
11,883 170
10,501 175
9,299 180
8,250 185
7,334 190
6,532 195
INSTALLATION AND OPERATION INSTRUCTIONS
RESISTANCE
°C Ω
38 5,828
41 5,210
43 4,665
46 4,184
49 3,760
52 3,383
54 3,050
57 2,754
60 2,490
63 2,255
66 2,045
68 1,857
71 1,689
74 1,538
77 1,403
79 1,281
82 1,172
85 1,073
88 983
91 903