Step-by-Step DIY Fix Guide
- SAFETY: Unplug the refrigerator.
- Reset by unplugging for 5 minutes, then restore power and check if FS clears.
- If FS returns, call an LG-authorized technician to test the freezer sensor and wiring harness.
If the warning comes back after restart
- If the warning returns immediately after a clean restart, the sensor or wiring path becomes more likely than a one-time glitch.
- FS persists after a 5-minute power reset
What This Error Means
Error FS on your LG refrigerator means: The freezer temperature sensor (thermistor) has shorted or become disconnected. The control board cannot monitor freezer temperature and cannot regulate the cooling cycle correctly. The refrigerator's self-diagnostic system has detected this condition.
The most frequent cause is freezer thermistor failure — resistance value is outside the valid range. Work through the causes and fix steps below in order — many LG refrigerator errors are resolved without a service call.
LG's official guidance classifies FS as a technician-only fault. A 5-minute power reset is the only DIY step — if the code returns, contact LG Support at 1-800-243-0000.
Sensor faults require professional diagnosis. A 5-minute power reset resolves transient communication glitches. If the code returns after a reset, the sensor or its wiring has physically failed and will not recover without replacement.
Most Likely Cause by Symptom
The LG refrigerator may stop, pause, or refuse to complete the cycle normally.
Likely cause: Freezer thermistor failure — resistance value is outside the valid range
Check first: SAFETY: Unplug the refrigerator.
The warning may return immediately because the appliance is detecting an internal fault.
Likely cause: Wiring harness connector to the freezer sensor has become loose or corroded
Check first: Reset by unplugging for 5 minutes, then restore power and check if FS clears.
Common Causes
- Freezer thermistor failure — resistance value is outside the valid range
- Wiring harness connector to the freezer sensor has become loose or corroded
- Sensor physically damaged by ice accumulation
What Not to Do
- Do not continue using the refrigerator for extended periods with FS active — unregulated freezer temperatures compromise food safety
Model and Display Variation Notes
Model-family notes
- LG refrigerator display wording and code formats can vary by series.
- If your model behaves differently, check the owner manual before trying any deeper maintenance step.
Display and panel differences
- Panel wording can vary by series, so confirm the exact code pattern before buying parts.
Parts, Tools and Service Options
Service option
LG service visit if the warning returns after the basic checks are complete.
Manual and model check
Check your exact model and manual before ordering any LG refrigerator parts.
Common parts
- Freezer thermistor/temperature sensor if sensor has failed ($15–$40)
This section stays service-first because the page points more strongly toward support or professional repair than a routine parts purchase.
When Not to Keep Troubleshooting
FS persists after a 5-minute power reset
How to Prevent It Recurring
- Keep the freezer door closed as much as possible — frequent warm-air exposure causes frost accumulation that can damage sensors over time
Related Error Codes
rS
The fresh food compartment temperature sensor (thermistor) has shorted or become disconnected. The control board cannot accurately monitor refrigerator temperature and may not cool the section correctly.
dS
The defrost sensor (thermistor that monitors evaporator temperature during the defrost cycle) has either shorted or become disconnected. Without a valid sensor reading, the control board cannot safely manage the defrost cycle.
FF
LG refrigerator error FF usually means the freezer evaporator fan is not circulating cold air through the cabinet properly.
Extra notes
- This page is based on LG support material and stays conservative where model-specific guidance may vary.
- The goal is to help you identify safe first checks before you move into parts, service, or model-specific manual lookup.
Source and model notes
Last reviewed: 2026-04-08
Based on: Based on LG support material and edited into consumer-safe guidance for the exact code family on this page.
Model coverage note: LG refrigerator code meanings can vary by series, control panel, and model family, so use this page as a safe starting point rather than a replacement for the model-specific manual.
Important: FixThisError is an independent guide, not the manufacturer. Use your model-specific manual when the panel wording or behavior differs.
Always disconnect power before inspecting appliances. If unsure, contact a licensed appliance technician.