Checking Temperature Sensors - Lochinvar ARMOR 151 - 801 Service Manual

The water heater temperature sensors (inlet water, outlet water, system water, and flue) are all resistance type devices. The
following tables show the correct values for the sensors at various temperatures. Use an ohmmeter to read the resistance of the
sensor at a known temperature. If the resistance of the sensor does not closely match its corresponding table, replace the sensor.
It is important to note that the flue and outlet water sensors have two temperature sensing devices in one housing. These devices
are designated as S1a/S1b, outlet sensor and S3a/S3b, flue sensor. Please reference the wiring diagram in the Armor Water Heater
Installation and Operation Manual for correct terminal location.
Table 3B -
50
68
86
104
122
140
Table 3C -
50 19,553
68 12,690
86 8,406
104 5,715
122 3,958
140 2,786
Table 3D -
50 40,030
68 25,030
86 16,090
104 10,610
122 7,166
140 4,943
26
Ω
18,780
12,263
8,194
5,592
3,893
2,760
158 2,004
176 1,464
194 1,084
212 816
158 3,478
176 2,492
194 1,816
212 1,344
158
176
194
212
--
--
50 40,030
68 25,030
86 16,090
104 10,610
122 7,166
140 4,943
50 258,500
68 125,500
86 80,220
104 52,590
122 35,270
140 24,160
Service Manual
Ω
1,990
1,458
1,084
817
--
--
158 3,478
176 2,492
194 1,816
212 1,344
158 16,870
176 12,000
194 8,674
212 6,369