Owner's manual

°F 012345678 9
40 26109 25400 24712 24045 23399 22771 22163 21573 21000 20445
50 19906 19383 18876 18383 17905 17440 16990 16553 16128 15715
60 15314 14925 14548 14180 13823 13477 13140 12812 12494 12185
70 11884 11592 11308 11032 10763 10502 10248 1000 9760 9526
80 9299 9078 8862 8653 8449 8250 8057 7869 7685 7507
90 7333 7165 7000 6839 6683 6531 6383 6238 6098 5961
100 582756975570544653265208509449824873 4767
110 466345624464436842744183409440063922 3839
120 375836793602352734533382331232443177 3112
130 304829862925286628082752269726432590 2538
140 248824392391234422982253220921662124 2083
150 204320041966192818911856182017861753 1720
160 168816561625159515661537150914811454 1427
170 140213761351132713031280125712351213 1191
180 117011501129111010901071195310351017 999
190 982 965 949 933 917 901 886 871 857 8 42
200 828 814 801 788 775 762 749 737 725 7 13
In Degrees F
Sensor Resistance at Various Temperatures
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
falls.
WARNING
Stored water may be HOT when performing the following steps in this procedure.
Take necessary precaution to prevent personal injury.
TTW SERVICE PROCEDURE VI
Gas Control/Thermal Well Testing and
Replacement
Determine Water Temperature Inside Tank (For water heaters with
serial numbers that begin with “J” or sooner.)
Step 1. Position gas control power switch to “OFF” position.
Step 2. Draw approximately 4 gallons of water from drain valve into a container 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 heater to drain.
Step 3. Using the chart below, determine correct resistance value for the water temperature from step 2.
Note: It is important to understand once the resistance for the thermal well is determined from page 24, water flow
through the heater should not occur. Prior to performing the steps below, turn off the cold water supply to the
water heater. This will prevent cold water flow into the tank affecting the resistance value of thermal well.
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