LG Refrigerator Error Code R-sensor open

The R-sensor open error means the refrigerator compartment temperature sensor has been detected as an open circuit by the control board. The MICOM reads a voltage above 4.5V at its sensor input, which corresponds to a temperature reading below -50°C and is outside any valid operating range. This is most commonly caused by a failed thermistor, a broken wire, or a disconnected connector in the sensor circuit. The refrigerator cannot regulate compartment temperature properly until the fault is resolved.

Continuing to run the refrigerator with this error is not recommended for extended periods. Without a valid temperature signal, the control board cannot accurately cycle the compressor and fans, which may result in the compartment running too warm or too cold. Food safety can be compromised if temperatures are not maintained properly. Address the fault as soon as possible and use a standalone thermometer to monitor compartment temperature in the interim if the refrigerator must stay in use.

A power reset may temporarily clear the error code from the display, but the fault will return as soon as the control board performs its next sensor check if the underlying problem has not been repaired. Resetting is useful for confirming whether the error is persistent or intermittent, but it is not a fix. The sensor circuit must be inspected and the faulty component corrected to permanently clear the error.

Many homeowners and DIYers can address this fault by inspecting and reseating the sensor wiring connector, which requires no special tools. If the sensor itself has failed, replacing an NTC thermistor is a straightforward repair that involves unplugging the old sensor and plugging in a compatible replacement. A multimeter is helpful for confirming whether the sensor or a wiring issue is the root cause before ordering parts. If the fault points to the main control board, that repair is more complex and may warrant professional service.

If the repair is limited to reseating a loose connector, there is no parts cost involved. A replacement R-sensor thermistor typically costs in the range of $15 to $50 depending on the specific model. If professional labor is required, expect to add $75 to $200 or more for a service call and diagnostic time. Control board replacement, if needed, is significantly more expensive and can range from $150 to $400 or higher for parts alone.