SERVICE PROCEDURE AG-III
Honeywell Thermowell Testing and
Replacemet
HONEYWELL THERMOWELL TESTING
Step 1. If gas control has gone into lockout due to excessive tank temperature (four flashes and a three second pause) reset the gas control to the “OFF” position. Then follow the instructions located on the lighting instruction label or the lighting instructions located in the installation and operation manual.
Step 2. Observe the water heater operation. If the gas control continues to lockout due to excessive tank temperature proceed to Step 3, thermowell testing, to determine the cause.
Step 3. To perform thermowell testing turn the gas control to the “OFF” position and disconnect the thermowell harness from the gas control.
Disconnect
thermowell wire
harness
Figure 28 |
| Figure 29 |
CAUTION |
DO NOT Use standard multimeter probes to test. Doing so will damage connector. Use special pin type electronic probes or small diameter wire pins inserted into connector
Figure 30
Step 4. Using a multimeter set to measure Ohms determine the resistance of the thermowell sensor (See caution on this page).
Step 5. Hold one probe in the center pin and measure the outside positions pins (see figure 29 & 30).
Step 6. Refer to Table 1 on page 17 to determine the correct resistance value for the water heater tank temperature.
Step 7. If the resistance values are correct the gas control needs to be replaced. If they are incorrect the thermowell needs to be replaced.
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