Quick Answer: Why Your LG Freezer Runs Too Cold#
Most likely: the freezer thermistor has drifted out of specification and is reporting the compartment as warmer than it actually is, so LG's control board keeps the variable-speed Linear Compressor running and the freezer overshoots its 0°F target. Because LG modulates compressor speed off that sensor rather than switching on and off, a bad reading quietly drives continuous cooling — often with no error code at all. The quick things to rule out first are an Ice Plus boost left running and a setpoint nudged by accident; after those, it is the sensor, the main board, or the inverter.
Likely Causes at a Glance#
| Cause | Likelihood | What to check |
|---|---|---|
| Freezer thermistor drift | 35% | freezer far below setpoint with no error code; sensor resistance off-spec |
| Setting error or Ice Plus left on | 25% | Ice Plus runs the compressor flat out for 24 hours; verify the setpoint |
| Main control board fault | 20% | overcooling continues even after a new thermistor; erratic display |
| Damper stuck open | 15% | both compartments run cold as air flows unregulated |
| Inverter board locked high | 5% | constant loud compressor clicking; an intermittent Er CO may show |
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Walking Through the Diagnosis#
Trust a real thermometer over the display, because LG's panel shows the setting, not the actual temperature. Put a digital thermometer in the center of the freezer for a couple of hours with the door shut, then compare it to the setpoint. If they disagree by more than about 5°F, the control system is at fault. Before opening anything, confirm Ice Plus is not active — it deliberately runs the compressor at maximum for 24 hours to make ice, and if it was triggered and forgotten the freezer will plunge — and check the setpoint has not been cycled by a stray button press.
If the setting is right and Ice Plus is off, test the sensor. Unplug the fridge, disconnect the freezer thermistor behind the rear panel, and read its resistance: an LG NTC sensor is around 16,000 to 18,000 ohms near 0°F and about 10,000 ohms near 32°F, so a value well off those means it has drifted and is reading warm. Swap it and monitor for 24 hours. If overcooling continues after a known-good thermistor, the fault has moved to the main board, which is ignoring the "temperature reached" signal and commanding continuous high-speed cooling — expect other glitches like phantom codes or an unresponsive panel alongside it. A rarer inverter-board fault locks the compressor at high output regardless of the board's commands, showing up as constant loud clicking with none of the normal quiet periods. And if both compartments run cold together, look instead at a damper stuck open, dumping unregulated freezer air across the fridge.
Repair or Replace? The Short Version#
A setting fix or a thermistor is cheap and clearly worth doing on an LG that otherwise runs — and running the freezer needlessly cold only wastes energy (roughly 15 to 30% more for every 5°F below 0°F) while degrading food, so it is worth correcting promptly. The main and inverter boards are the costlier calls, yet still under the price of a new refrigerator; note too that LG's compressor warranty covers the compressor, not these regulation parts. If a new sensor does not settle it and the compressor never eases off, have the boards checked — book a repair.
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Frequently Asked Questions#
Why is my LG freezer too cold but the fridge is fine?#
That split usually means the damper is metering the fridge correctly while the freezer's own feedback is off — most often a thermistor reading the freezer as warmer than it is, so the board keeps cooling that section. Test the freezer thermistor's resistance against its spec before replacing anything else.
Does the LG display show the real freezer temperature?#
No — it shows the setpoint you chose, not the measured temperature. Put an independent thermometer inside for a couple of hours; if it reads more than about 5°F colder than the setpoint, a control fault (usually the thermistor) is overcooling the freezer.
Could the Ice Plus feature be making my freezer too cold?#
Yes. Ice Plus runs the compressor at maximum for 24 hours to speed ice production, so if it was switched on and left, the freezer overcools until it ends. Check for the Ice Plus indicator and turn it off, then let the temperature stabilize for a day.
Is running my LG freezer colder than 0°F harmful?#
Not to the appliance, but it wastes energy and worsens freezer burn. The FDA recommends 0°F, and colder adds no food-safety benefit while raising consumption by roughly 15 to 30% for every 5°F below zero, so persistent overcooling signals a fault worth fixing.
Senior Appliance Repair Technician · 15 years experience
EPA-certified technician with 15 years of experience specializing in refrigerator and cooling system repairs.
