THERMOCOUPLE REPLACEMENT
Step 1. Turn off gas supply to wat er heater. Rotate knob of gas control to “OFF” posi tion.
Step 2. Remove outer jacket door.
Step 3. Slide open inner combustion chamber door.
Step 4. Disconnect thermocouple from gas control. Locate other end of
thermocouple inside of combus tion chamber and remove from pil ot bracket. Pull firmly pullin g away
from the pilot assembly.
Step 5. Install new thermocouple into pilot bracket making certain th e thermocouple is fully eng aged into the pilot
bracket. Connect other end of thermocouple to gas control (finger tight + ¼ turn).
Step 6. Route carefully through the relief opening in the combustion chamber skirt.
Step 7. To resume operation follow the instructions located on the lighting instruction label or the lighting
instructions located in the installation and operation manual.
Step 8. Slide inner door closed when finished.
SERVICE PROCEDURE AG-I
Thermocouple Testing and Replacement
For Models Using White Rodgers or
Robertshaw Gas Control
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Figure 3
For White Rodgers gas
control, depress knob
slightly and rotate
clockwise to the “OFF”
position.
For Robertshaw gas
control, rotate knob
clockwise to the “OFF”
position.
Step 1. Disconnect thermocouple from gas control.
Step 2. Using a multimeter capable o f measuring millivolts, conn ect
one alligator clip to the end ball or contact portion of the
thermocouple, and the other all igator clip to copper portion of
the thermocouple.
Step 3. Following the lighting instru ction label on the heater , proceed to light the pilot and allow to operate for
three minutes. A reading of 20 to 30 millivolts indicates go od thermocouple output.
OPEN CIRCUIT THERMOCOUPLE TESTING
Figure 4
Thermocouple position
Figure 1
Figure 2
NOTE:
It will be necessary to hold the gas control
knob down in the “PILOT” position
continuously throughout this test.
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