Determine Water Temperature; Sensor Resistance At Various Temperatures - Bradford White Defender RG130T Series Service Manual

Stored water may be HOT when performing the following steps in this
procedure. Take necessary precaution to prevent personal injury.

DETERMINE WATER TEMPERATURE

INSIDE TANK
NOTE: It is important to understand once the resistance for the temperature sensor is determined from
the previous page, water flow through the water heater should not occur. Prior to drawing
water from drain valve, turn off the cold-water supply to the water heater. This will prevent cold
water flow into the tank, affecting the resistance value of the temperature sensor.
Set the gas control knob to the "OFF" position. Turn off inlet water supply to water heater.
Step 1.
Draw approximately 4 gallons of water from drain valve into a container, or suitable drain, and
Step 2.
discard. Draw an additional gallon and immediately measure water temperature using an accurate
thermometer. It may be necessary to open a hot water faucet to allow water heater to drain.
Using the chart below, determine correct resistance value for the water temperature from Step 2.
Step 3.
Example: If temperature of water is 84°F, then the resistance through
the sensor would be 8449 (see shaded area).
NOTE: Sensor resistance increases as the temperature decreases.
°F 0
40 26109
50 19906
60 15314
70 11884
80 9299
90 7333
100 5827
110 4663
120 3758
130 3048
140 2488
150 2043
160 1688
170 1402
180 1170
190 982
200 828

Sensor Resistance at Various Temperatures

In Degrees F
1 2 3
25400 24712 24045
19383 18876 18383
14925 14548 14180
11592 11308 11032
9078 8862 8653
7165 7000 6839
5697 5570 5446
4562 4464 4368
3679 3602 3527
2986 2925 2866
2439 2391 2344
2004 1966 1928
1656 1625 1595
1376 1351 1327
1150 1129 1110
965 949 933
814 801 788
SERVICE PROCEDURE RG-VI
Gas Control Testing, Disassembly, & R eplacement
WARNING
4 5 6
23399 22771 22163
17905 17440 16990
13823 13477 13140
10763 10502 10248
8449 8250 8057
6683 6531 6383
5326 5208 5094
4274 4183 4094
3453 3382 3312
2808 2752 2697
2298 2253 2209
1891 1856 1820
1566 1537 1509
1303 1280 1257
1090 1071 1053
917 901 886
775 762 749
31
(Honeywell ONLY)
7 8 9
21573 21000 20445
16553 16128 15715
12812 12494 12185
10000 9760 9526
7869 7685 7507
6238 6098 5961
4982 4873 4767
4006 3922 3839
3244 3177 3112
2643 2590 2538
2166 2124 2083
1786 1753 1720
1481 1454 1427
1235 1213 1191
1035 1017 999
871 857 842
737 725 713
31