LG Oven TCO Error: Over-temp protection activated
LG oven error — here’s what you need to know. The tCO error code on your LG oven indicates catalytic converter over-temperature protection activated. This is a High severity issue. What Does tCO Mean on an LG Oven? The tCO error code means the oven’s thermal over-temperature cutout (thermal cut-off) has been activated — the […]
~25%
DIY Fixable
From 80
Typical Repair Cost
60–150 min
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
No. Do not attempt to use or reset the oven until the cause of the over-temperature event has been identified. Operating the oven with an unresolved relay or sensor fault that caused tCO creates a serious fire risk.
Can I reset the code?
Yes. tCO cannot be cleared by power cycling alone. The thermal cutout device must be physically reset (if resettable) or replaced, and the root cause of the over-temperature condition must be corrected first.
When to stop immediately?
Stop if you notice: Stop and call a technician immediately — do not attempt to bypass the thermal cutout to restore oven operation., Stop if the oven continues to feel abnormally hot after being turned off — a welded relay may still be energizing an element..
Symptoms You May Notice
Oven stops heating and will not restart
The thermal cutout has opened the heating circuit as a safety measure; the oven will display tCO and refuse to energize any heating element until the cutout is reset or replaced.
tCO code on the display
The oven shows tCO on the display — this code does not clear with a simple power cycle because the thermal cutout remains tripped until the oven cools and the cutout is addressed.
Oven interior may feel excessively hot even after being turned off
If a welded relay caused the tCO fault, the bake or broil element was continuously energized and the oven cavity may retain abnormal heat well after the cutout tripped.
Inconsistent temperature performance
The oven runs too hot, too cold, or cycles erratically because the control board receives inaccurate temperature readings from the faulty sensor.
Possible Causes
Faulty temperature sensor causing oven to overshoot
An inaccurate sensor reports a lower-than-actual temperature, causing the control board to keep the element on past the safe limit until the thermal cutout activates.
DIY PossibleWelded relay keeping the heating element continuously on
A relay contact on the control board has welded closed, energizing the bake or broil element continuously without the control board's knowledge, rapidly driving temperatures beyond the cutout threshold.
Requires ProfessionalTripped or failed thermal cutout (thermal fuse)
The thermal cutout device itself has tripped in response to a genuine over-temperature event and must be replaced after the root cause is identified and corrected.
Requires ProfessionalSafe Checks You Can Do
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1
Allow the oven to cool completely — do not open the door
If tCO appeared during use, let the oven cool with the door closed for at least 30–45 minutes. Sudden temperature change from opening the door can stress the oven cavity components.
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2
Check for obvious causes before resetting
Before attempting any reset, consider what the oven was doing when tCO appeared — a self-clean cycle with a heavily soiled oven or an extremely long unattended bake are lower-risk triggers. Restarting without investigating a relay or sensor fault risks triggering tCO again.
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3
Locate and test the thermal cutout
With the oven circuit off, access the thermal cutout (location varies by model — consult your service manual; typically found on the oven cavity exterior or near the control board). Use a multimeter to test continuity across the cutout terminals. No continuity confirms it has tripped.
When to Call a Professional
Contact a qualified technician if:
- The thermal cutout has confirmed tripped — root cause diagnosis is required before replacement.
- A welded relay is suspected — the control board must be replaced.
- tCO returns after replacing the thermal cutout, indicating the underlying fault has not been corrected.
Need Professional Help?
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