What does LG Refrigerator FS Error Code - Causes & Fix mean?

FS means the freezer temperature sensor is shorted or open. The fix is usually a new freezer thermistor after checking the wiring.

How do I fix LG Refrigerator FS Error Code - Causes & Fix?

Follow the step-by-step diagnosis below. The most likely fix is identified by checking power, sensor resistance, and control-board signals in order — using a multimeter and the part numbers documented in the parts reference table.

Can I keep running the equipment with this fault active?

Generally no. Faults on Appliance units are emitted when a sensor, safety, or control circuit is outside its operating envelope. Running through an active fault risks compressor, heater, or control-board damage. Diagnose and clear the fault first.

What part is most commonly replaced for LG Refrigerator FS Error Code - Causes & Fix?

The most frequently replaced parts for LG Refrigerator FS Error Code - Causes & Fix are listed in the Parts Reference section of this guide with OEM part numbers and typical price ranges. Check the table for direct replacements.

Is LG Refrigerator FS Error Code - Causes & Fix a DIY repair or do I need a technician?

Sensor swaps, fan motor replacements, and condenser cleaning are typical DIY-level repairs. Anything involving refrigerant, gas, or high-voltage (>240V) work requires a licensed technician for both safety and code-compliance reasons.

LG Refrigerator FS Error Code - Causes & Fix

LG Refrigerator FS Error Code — What It Means

The FS code (shown as Er FS) means the freezer temperature sensor, also called the freezer thermistor, is reading as a short or an open circuit. The main board relies on this sensor to know the freezer temperature, so a bad reading throws FS and cooling control suffers.

The usual causes are a failed thermistor, a damaged wiring connector, or moisture in the sensor circuit. The control board is the last item to check.

Jump to Fix

Common Causes

Failed freezer thermistor A sensor that has shorted or opened internally gives the board an out of range reading.
Loose sensor connector A connector that backed out or corroded breaks the circuit between the sensor and the board.
Moisture or water damage Water reaching the sensor or its wiring corrodes pins and causes a false short or open.
Pinched or chafed wiring A wire pinched during a prior repair can break the sensor circuit over time.
Main control board fault A board that misreads the sensor input can post FS even with a good thermistor.

Step-by-Step Fix

Unplug the refrigerator or trip the breaker for about 30 seconds, then restore power to see if FS clears.
Locate the freezer thermistor and inspect its connector for looseness, corrosion, or moisture.
Reseat the connector firmly and clean any corrosion you find on the pins.
Check the wiring along its run for pinch points or chafing and repair any damage.
Measure the thermistor resistance with a multimeter and compare it against the value for the freezer temperature.
Replace the freezer thermistor if the resistance is out of range or reads open or shorted.
If a new sensor and clean wiring still show FS, replace the main control board.

Parts Often Needed

Part	Notes
LG freezer thermistor temperature sensor	Amazon \| Match by model number. Confirm the connector style before ordering.
Sensor wiring harness or connector	Amazon \| Only if the existing harness is corroded or pinched.
LG refrigerator main control board	Amazon \| Replace last, after the sensor and wiring test good.

When to Call a Pro

Call a technician if FS returns after a new thermistor and verified wiring. A code that survives a good sensor usually points to a board or harness fault that needs careful meter work to confirm.