Er rS Serious Moderate DIY

LG Refrigerator Er rS — Refrigerator (fresh-food) sensor open/disconnected

LG Refrigerator · Error code Er rS

What Er rS Means

The fresh-food compartment thermistor is reading open or is unplugged from the main board, so the unit can't regulate fridge temperature.

Symptoms

  • Er rS on display
  • Fresh-food side too cold or too warm
  • Compressor may run constantly or short-cycle

Common Causes

1
Disconnected sensor plug

Vibration or recent service left the connector unseated.

2
Open thermistor

NTC sensor failed internally.

3
Damaged harness

Wire chafed at a hinge or shelf bracket.

4
Main board input failure

Rare — sensor channel on PCB dead.

How to Fix It

  1. Unplug the refrigerator.
  2. Remove the fresh-food rear panel or sensor cover and locate the thermistor.
  3. Inspect the harness connector and reseat it firmly.
  4. Ohm the thermistor at a known room temperature against LG spec sheet.
  5. If out of range or open, replace the sensor (kit usually inexpensive).
  6. Restore power and confirm Er rS clears.

Parts You May Need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Common replacement Fresh-food thermistor View on Amazon→

More LG Refrigerator Codes

22 22 — Compressor relay / inverter control fault 33 33 — Compressor / defrost test fault 67 67 — Door open / not fully closed 88 88 — Power-on display test (not a fault) Er CF Er CF — Condenser Fan Fault Er CO Er CO — Compressor / Communication Fault

All LG codes → All refrigerator codes →

Verified against manufacturer documentation: lg.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.