FIXED LSWS305ST LG Wall oven Thermostat AND thermal fuse

phemfrog

Premium Member
Joined
Oct 29, 2018
Messages
6
Location
Texas
Model Number
LSWS305ST
Brand
LG
Age
6-10 years
Hello, I am in need of help.

My LG wall oven blew the thermal fuse 6930W1A003X a few years ago after a self clean. I did not use the self clean cycle again.

Since then, the thermal fuse has blown 2 more times, and the thermostat EBG51439303 (another fuse type one on the back of the unit) has failed twice. I have had to take my oven out of the wall 4 times. This is getting frustrating to say the least.

One thing i notice is that each fuse I remove has melted plastic near the leads (the metal tabs that you connect the wires to). This does not look like it melted from external heat (the rest of the plastic on the fuse is fine). I will post a photo.

Is there something else that could be causing these repeated failures? How would I go about diagnosing this?

HELP. I am sick of pulling the oven out. Yesterday it happened when i tried to use the oven on convection bake at 450 degrees. :mad:

20181029_121154.jpg
 

rickgburton

Appliance Tech - Moderator
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Messages
34,041
Location
Murray, Utah 84107, United States
Take the wire that was on the melted t-stat terminal and cut the wire end off. Strip the wire back about an inch and check the wire strands. If they are not shiny and look dull that's probably causing the problem. Make sure all the wire connectors are on tight. Even though the other end is not melted that wire can be bad also. Check the wires on any part you've replaced. If there's a gap between the wire insulation and the wire end it's a good indication the wire is breaking down.
 

phemfrog

Premium Member
Joined
Oct 29, 2018
Messages
6
Location
Texas
Okay, so I can do that. But i have one question. As i mentioned in my post, there are 2 separate thermal fuses in this oven. BOTH of the fuses have melted like this. It seems unlikely to be a wire issue, because it would have to affect 2 different wires on 2 different parts. Does that kind of thing happen?

Could this be something with one of the circuit boards?

Also, I installed the oven in a cabinet with ample room behind the oven (4" more than spec), but it does not get any air flow back there. Could this be a problem? There is nothing in the installation manual about air inside the cabinet, and the oven has an intake and a vent on the front. I do notice, however, that there are air vents on the back of the oven cabinet.

Thanks.
 

rickgburton

Appliance Tech - Moderator
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Messages
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The 4" is fine. The main problem is it's an LG. I've replaced a lot of those TCO's on LG ovens and ranges more than any other brand.
 

phemfrog

Premium Member
Joined
Oct 29, 2018
Messages
6
Location
Texas
The 4" is fine. The main problem is it's an LG. I've replaced a lot of those TCO's on LG ovens and ranges more than any other brand.
So would it be feasible to replace the wiring, or would that be a job too big to try?
 

rickgburton

Appliance Tech - Moderator
Staff member
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Messages
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You don't need to replace the entire wiring harness (a big job). Just cut off the bad wire, about an inch or two, and replace the wire terminal/end.
 

phemfrog

Premium Member
Joined
Oct 29, 2018
Messages
6
Location
Texas
Sorry for so many questions, but i have one more.

In my original post, you can see that I have had to replace both of the thermal fuses in this oven. So i likely have more than 1 bad wire...

Does this change your thoughts on the problem at all?

thanks.
 

phemfrog

Premium Member
Joined
Oct 29, 2018
Messages
6
Location
Texas
In the end

Maybe four bad wires. I made you a diagram:
View attachment 40375
So i decided to just replace the fuses one last time. The wiring looked too big a job to undertake. What i did do was ventilate the wall where it is mounted better (basically left a gap above the oven). I also don't use self-clean anymore. So far i have made it a few months with no failures.

I will likely just replace the fuses until something else breaks and i have to replace the whole oven.
 
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