Bradford White TW4-75S-76B-3X - Manual (Page 17)

TTW SERVICE PROCEDURE II
Pilot testing, Cleaning and Replacement
Pilot Inspection, Testing and Replacement
Step 1. Position gas control power switch to the
“OFF” position and unplug heater from wall
outlet.
Step 2. Turn off gas supply to water heater.
Step 3. Remove outer jacket door and slide inner door open from left to
right.
Remove Outer
door.
Slide inner door open
from left to right.
Feedline nut
Pilot tubing nut
Igniter/flame
sense wire
Step 4. Disconnect pilot tube nut (7/16 wrench) and feedline nut
(¾ wrench) from gas control.
Step 5. Disconnect igniter/flame sense wire from gas control.
Step 6. Remove burner assembly from combustion chamber.
Step 7. Remove pilot assembly from feedline (¼" nut driver).
Step 8. Visually inspect igniter/flame sense wire for damage. Replace
pilot if damage is found.
Step 9. With a multi-meter set to the ohms setting, check continuity
through igniter/flame sense wire. Replace pilot if no continuity.
Step 10. Visually inspect igniter/flame sense electrode for deterioration.
Replace pilot as necessary. Electrode should not be in contact
with pilot hood, If so, carefully adjust electrode to a gap
distance of 3/32" (.09) from pilot hood.
Step 11. Visually inspect igniter/flame sense electrode for oxidation
build up. Carefully clean any oxidation using very fine emery
cloth.
Step 13. Inspect pilot tubing and pilot orifice for blockage:
a) Remove ferrule nut from bottom of pilot assembly (7/16" wrench).
b) Remove pilot tube and pilot orifice.
c) Inspect pilot tubing and pilot orifice for blockage. Clean
or replace as necessary.
Step 14. Reassemble pilot and install to feedline. Reinstall burner assembly to water heater. Restore gas supply
and check for gas leaks.
Step 15 To resume operation follow the instruction located on the lighting instruction label or the lighting
instruction located in the installation and operating manual.
Step 12. Visually inspect pilot tubing for kinks or cracks. If damage is
found replace pilot.
Ferrule
nut
Pilot
orifice
Pilot
hood
Igniter/flame
sense electrode
Igniter/flame
sense wire
Pilot
tubing
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