LG Refrigerator rT Error Code — What It Means
The rT error code on your LG refrigerator indicates an open or shorted room temperature sensor in the fresh-food compartment. The control board is not receiving a valid signal from the refrigerator compartment thermistor. This is an electrical sensor circuit fault, not a general cooling issue. LG’s own documentation confirms rT points specifically to a shortened or open room temperature sensor circuit and states there are no DIY troubleshooting steps beyond service inspection.
Common Causes
- Failed refrigerator compartment thermistor The room temperature sensor itself has either failed open circuit or shorted, the most common cause of this code.
- Loose or corroded sensor connector The wiring connector at the thermistor has worked loose, corroded, or developed damaged terminals that break the circuit.
- Damaged sensor wiring harness The wire run between the sensor and the control board has been cut, pinched, or abraded, creating an open or intermittent short.
- Main control board input failure The control board itself is unable to read the sensor circuit correctly, though this is less common than a bad sensor or wiring issue.
Step-by-Step Fix
- {‘step’: ‘Verify the code by confirming the display shows rT and not a similar LG fault code, and note your exact model number for reference.’}
- {‘step’: ‘Power reset the unit by unplugging the refrigerator (or tripping the breaker) for 5 minutes, then restore power and check if the code returns.’}
- {‘step’: ‘Locate and inspect the refrigerator compartment room temperature sensor (thermistor), its wiring harness, and the connector terminals for visible damage, looseness, or corrosion.’}
- {‘step’: “Measure sensor resistance at the thermistor connector using a multimeter and compare the reading to your model’s service data specification.”}
- {‘step’: ‘Replace the room temperature sensor if it reads open, shorted, or out of specification for the measured compartment temperature.’}
- {‘step’: ‘Repair or replace the sensor harness and connector if you find cut wires, damaged insulation, or corroded terminals.’}
- {‘step’: ‘Replace the main control board only after confirming the sensor and wiring test normal but the code persists, indicating a board input fault.’}
Parts Often Needed
| Part | Notes |
|---|---|
| LG refrigerator room temperature sensor / fresh-food thermistor | Amazon | Match to your exact LG model number, as thermistor specs vary by platform. |
| Refrigerator thermistor wiring harness | Amazon | Order if the wire run or connector is damaged and not easily repaired. |
| LG refrigerator main control board / PCB | Amazon | Replace only after verifying the sensor circuit tests good but the error persists. |
When to Call a Pro
LG’s official support documentation states there are no DIY troubleshooting steps for the rT code beyond requesting service inspection. If you are not comfortable working with live electrical circuits, testing thermistor resistance, or accessing components inside a sealed refrigerator compartment, call a qualified appliance technician. A professional has the model-specific service data, OEM thermistor resistance tables, and tools to safely diagnose the sensor circuit and control board inputs. If the code reappears immediately after a power reset or you see other fault codes along with rT, professional diagnosis is the best path.