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Video & Articles: Appliance & Equipment RepairAO Smith Gas Water Heater 24" Thermocouple Replacement 9000056045 
AO Smith Gas Water Heater 24" Thermocouple Replacement 9000056045
Skill Level
Total Parts Cost
$14.25Estimated Savings
$112.5007:13
- Description
This video provides step-by-step instructions for replacing the 24" thermocouple on AO Smith gas water heaters. The most common reasons for replacing this part is if the burner will not light or stay lit.
All of the information in this thermostat replacement video is applicable to the following brands: AO Smith
All of the information in this thermostat replacement video is applicable to the following brands: AO Smith
Step By Step Instructions
1
To replace the thermocouple in this a.o. smith gas water heater…
2
… you will need a 7/16th inch wrench, a 3/8th inch wrench, an adjustable wrench, a quarter-inch nut driver, a flat-head screwdriver, a phillips-head screwdriver, and needle-nose pliers.
3
Before you begin the procedure, shut off the gas supply to the unit.
4
Detach the outer burner tube assembly cover.
5
Disconnect the safety thermostat wires…
6
… as well as the spark wire.
7
Use the 7/16th inch wrench to unthread the compression nut to detach the pilot gas tube from the gas valve.
8
Use the 3/8th inch wrench to unthread the nut to release the thermocouple from the valve.
9
Now use the adjustable wrench to unthread the nut to release the main burner tube from the valve.
10
Use the quarter-inch nut driver to unthread the two mounting screws securing the burner tube assembly.
11
With the screws unthreaded, you can pull the burner tube assembly out.
12
For better access to the thermocouple, turn the assembly upside down…
13
… and use the phillips-head screwdriver to unthread the two mounting screws to release the burner head.
14
Turn the assembly upright…
15
… and use the flat-head screwdriver and needle-nose pliers to detach the retaining clip securing the insulator block.
16
Note the positioning of the wires and tube… then remove the two halves of the block.
17
You can now fully remove the old thermocouple by pulling it free of the pilot assembly bracket.
18
To prepare the new thermocouple for installation…
19
… use needle-nose pliers to depress the tabs to release the old thermocouple retainer from the pilot assembly mounting bracket.
20
Insert the provided thermocouple retainer into the mounting bracket and snap it into place.
21
Unwind the new thermocouple wire.
22
Now insert the thermocouple through the bracket and into the retainer.
23
Properly orientate the wires and tube…
24
… then reassemble the two halves of the insulator block.
25
Snap the retaining clip into place to secure.
26
Turn the assembly upside down, then align the burner head…
27
… and thread the two mounting screws to secure.
28
Reinstall the burner assembly by…
29
… positioning it in the tank opening so the tab on the front of the assembly is inserted into the bracket in the tank cavity.
30
Thread the two mounting screws to secure the assembly.
31
Insert the pilot gas tube into the gas valve and secure with the nut.
32
Insert the main burner tube into the valve and thread the nut to secure.
33
Next, insert the thermocouple and tighten the nut.
34
Attach the spark wire to the spark igniter wire on the valve.
35
Connect the safety thermostat wires to the terminals.
36
Reinstall the burner tube assembly cover.
37
Turn the gas supply back on.
38
With the burner on, you can check the main burner tube and the pilot tube for leaks using a soap and water solution.
Description
This video provides step-by-step instructions for replacing the 24" thermocouple on AO Smith gas water heaters. The most common reasons for replacing this part is if the burner will not light or stay lit.
All of the information in this thermostat replacement video is applicable to the following brands: AO Smith
All of the information in this thermostat replacement video is applicable to the following brands: AO Smith
Step-By-Step Instructions
1
To replace the thermocouple in this a.o. smith gas water heater…
2
… you will need a 7/16th inch wrench, a 3/8th inch wrench, an adjustable wrench, a quarter-inch nut driver, a flat-head screwdriver, a phillips-head screwdriver, and needle-nose pliers.
3
Before you begin the procedure, shut off the gas supply to the unit.
4
Detach the outer burner tube assembly cover.
5
Disconnect the safety thermostat wires…
6
… as well as the spark wire.
7
Use the 7/16th inch wrench to unthread the compression nut to detach the pilot gas tube from the gas valve.
8
Use the 3/8th inch wrench to unthread the nut to release the thermocouple from the valve.
9
Now use the adjustable wrench to unthread the nut to release the main burner tube from the valve.
10
Use the quarter-inch nut driver to unthread the two mounting screws securing the burner tube assembly.
11
With the screws unthreaded, you can pull the burner tube assembly out.
12
For better access to the thermocouple, turn the assembly upside down…
13
… and use the phillips-head screwdriver to unthread the two mounting screws to release the burner head.
14
Turn the assembly upright…
15
… and use the flat-head screwdriver and needle-nose pliers to detach the retaining clip securing the insulator block.
16
Note the positioning of the wires and tube… then remove the two halves of the block.
17
You can now fully remove the old thermocouple by pulling it free of the pilot assembly bracket.
18
To prepare the new thermocouple for installation…
19
… use needle-nose pliers to depress the tabs to release the old thermocouple retainer from the pilot assembly mounting bracket.
20
Insert the provided thermocouple retainer into the mounting bracket and snap it into place.
21
Unwind the new thermocouple wire.
22
Now insert the thermocouple through the bracket and into the retainer.
23
Properly orientate the wires and tube…
24
… then reassemble the two halves of the insulator block.
25
Snap the retaining clip into place to secure.
26
Turn the assembly upside down, then align the burner head…
27
… and thread the two mounting screws to secure.
28
Reinstall the burner assembly by…
29
… positioning it in the tank opening so the tab on the front of the assembly is inserted into the bracket in the tank cavity.
30
Thread the two mounting screws to secure the assembly.
31
Insert the pilot gas tube into the gas valve and secure with the nut.
32
Insert the main burner tube into the valve and thread the nut to secure.
33
Next, insert the thermocouple and tighten the nut.
34
Attach the spark wire to the spark igniter wire on the valve.
35
Connect the safety thermostat wires to the terminals.
36
Reinstall the burner tube assembly cover.
37
Turn the gas supply back on.
38
With the burner on, you can check the main burner tube and the pilot tube for leaks using a soap and water solution.
Applicable Product Model
Parts Needed
Thermocouple
$14.25
Total$0.00
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