The Bradford White
SERVICE PROCEDURE V
Gas Control
Testing, Disassembly & Replacement
WARNING
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.
Step 1. Set the Gas Control knob to the “OFF” position.
Step 2. Turn off inlet water supply to water heater.
Step 3. Draw approximately 4 gallons of water from drain valve into a container, or suitable drain, and 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.
Step 4. Using the chart below, determine correct resistance value for the water temperature from step 3.
Example: | If temperature of water is 84°F, then the resistance through the sensor would be | |||||||||||||||
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| 8449 (see shaded area). NOTE: Sensor resistance increases as the temperature |
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| Sensor Resistance at Various Temperatures |
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| In Degrees F |
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| °F | 0 | 1 |
| 2 | 3 |
| 4 | 5 | 6 | 7 |
| 8 |
| 9 | |
| 40 | 26109 | 25400 | 24712 | 24045 |
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| 23399 | 22771 | 22163 | 21573 | 21000 |
| 20445 | ||
| 50 | 19906 | 19383 | 18876 | 18383 |
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| 17905 | 17440 | 16990 | 16553 | 16128 |
| 15715 | ||
| 60 | 15314 | 14925 | 14548 | 14180 |
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| 13823 | 13477 | 13140 | 12812 | 12494 |
| 12185 | ||
| 70 | 11884 | 11592 | 11308 | 11032 |
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| 10763 | 10502 | 10248 | 10000 | 9760 |
| 9526 | ||
| 80 | 9299 | 9078 | 8862 | 8653 |
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| 8449 | 8250 | 8057 | 7869 | 7685 |
| 7507 | ||
| 90 | 7333 | 7165 | 7000 | 6839 |
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| 6683 | 6531 | 6383 | 6238 | 6098 |
| 5961 | ||
| 100 | 5827 | 5697 | 5570 | 5446 |
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| 5326 | 5208 | 5094 | 4982 | 4873 |
| 4767 | ||
| 110 | 4663 | 4562 | 4464 | 4368 |
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| 4274 | 4183 | 4094 | 4006 | 3922 |
| 3839 | ||
| 120 | 3758 | 3679 | 3602 | 3527 |
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| 3453 | 3382 | 3312 | 3244 | 3177 |
| 3112 | ||
| 130 | 3048 | 2986 | 2925 | 2866 |
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| 2808 | 2752 | 2697 | 2643 | 2590 |
| 2538 | ||
| 140 | 2488 | 2439 | 2391 | 2344 |
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| 2298 | 2253 | 2209 | 2166 | 2124 |
| 2083 | ||
| 150 | 2043 | 2004 | 1966 | 1928 |
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| 1891 | 1856 | 1820 | 1786 | 1753 |
| 1720 | ||
| 160 | 1688 | 1656 | 1625 | 1595 |
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| 1566 | 1537 | 1509 | 1481 | 1454 |
| 1427 | ||
| 170 | 1402 | 1376 | 1351 | 1327 |
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| 1303 | 1280 | 1257 | 1235 | 1213 |
| 1191 | ||
| 180 | 1170 | 1150 | 1129 | 1110 |
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| 1090 | 1071 | 1953 | 1035 | 1017 |
| 999 | ||
| 190 | 982 | 965 |
| 949 | 933 |
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| 917 | 901 | 886 | 871 | 857 |
| 842 | |
| 200 | 828 | 814 |
| 801 | 788 |
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| 775 | 762 | 749 | 737 | 725 |
| 713 | |
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| 15 |
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15
