LG Refrigerator Error Code Er FS: Freezer Sensor Shorted or Open
$59 diagnostic β FREE with repair | 90-day warranty on parts & labor
What Our Customers Say
"I am so happy with the services provided by TruePro Home Services! I have a very old oven that I truly believed would need to be replaced. But, Yury came on time, diagnosed the issues, and had the parts with him to do the repair the same day. My oven is now in perfect working order. Highly recommend!"
Jill W.
Thousand Oaks
"Our LG Front Loading washer wasn't draining. I contacted Simon the next day. He had the part on his truck and came by within 30 minutes, and had it up and running super fast! Thank you Simon for your punctuality, honesty and great value. See you next time!"
Julia M.
Oxnard
"Wonderful and top notched care! They were able to meet my same day expectation to get a washer and dryer hooked up in a new house. He was attentive, thoughtful and explained it all as well. I would highly recommend their service!"
Aleema B.
Simi Valley
What Error Code Er FS Means
The Er FS code means the freezer temperature sensor (thermistor) has failed. This sensor is a small bead or probe mounted on or near the evaporator that reports the freezer temperature to the main control board. A shorted or open sensor sends an incorrect reading, causing the board to run the compressor too much, too little, or not at all. You get a freezer that is either too warm or frozen solid.
Common Causes
Open thermistor circuit
The thermistor wire breaks internally or at its solder joint. The board reads infinite resistance and triggers Er FS.
Shorted thermistor
Moisture infiltration shorts the thermistor element. The board reads near-zero resistance, interprets it as an extremely high temperature, and runs the compressor nonstop.
Damaged sensor harness
The thin wires connecting the thermistor to the main board get pinched or cracked by the evaporator cover, ice buildup, or vibration.
Main control board failure
The analog-to-digital converter circuit on the board that reads the sensor signal fails. The sensor itself is fine. This is rare but happens on older units.
How to Fix It
- 1
Reset the refrigerator
Unplug the unit for 5 minutes. Plug it back in. If Er FS clears and does not return within a few hours, a temporary glitch caused the error. Monitor the freezer temperature for 24 hours.
- 2
Locate the freezer sensor
Open the freezer door. Remove the rear evaporator cover panel (Phillips screws). The freezer thermistor is typically clipped to the evaporator tubing or mounted on the evaporator housing. It is a small plastic-coated bead with two thin wires.
Unplug the refrigerator before removing any panels or disconnecting sensors.
- 3
Test the thermistor with a multimeter
Disconnect the thermistor harness. Set your multimeter to the 20K-ohm range. At room temperature (around 77 degrees F), a typical LG freezer thermistor reads approximately 5,000 ohms (5K). At freezer temperature (around 0 degrees F), it reads roughly 16,000-17,000 ohms. OL or zero ohms means the sensor has failed. Replace it.
- 4
Inspect the sensor wiring
Trace the two sensor wires from the thermistor back to the main harness connector. Look for cuts, pinch points, or corroded splices. Repair damaged wires with butt connectors and heat-shrink tubing.
- 5
Replace the thermistor
Order the correct freezer thermistor for your LG model number (check the model tag inside the fresh food section). Unclip the old sensor from the evaporator. Clip the new one in the same location. Route the wires along the same path and connect the harness. Reinstall the evaporator cover.
When to Call a Professional
A thermistor replacement is a quick repair for a trained technician. If your sensor reads correctly but the code persists, the main control board needs diagnosis. TruePro's $59 diagnostic is credited toward the repair. All sensor and board replacements carry a 90-day parts and labor warranty. CA License #51112. Same-day service is often available in LA County, Orange County, and Ventura County. Call 877-378-3111. First-time customers get 15% off labor with code NEW15.
Estimated Repair Cost
| Option | Estimated Cost |
|---|---|
| DIY (parts only) | $15 - $45 |
| Professional repair | $140 - $260 |
DIY covers the thermistor part, which is inexpensive. Professional range includes diagnosis and labor. Main control board replacement raises the total to $350-$500.
See full refrigerator repair cost breakdown βLG Refrigerator Er FS β FAQ
Related LG Error Codes
Ready to get your appliance fixed?
Book online in minutes or call for same-day availability.
90-day warranty β’ Upfront pricing β’ No hidden fees