U-Line Refrigerator Error Code R Zone T Short

The R Zone T Short error on a U-Line refrigerator indicates that the thermistor circuit monitoring the right refrigeration zone has developed a short circuit condition. A thermistor is a temperature-sensitive resistor that changes resistance value in response to temperature changes, allowing the control board to monitor zone temperatures and regulate compressor and fan operation accordingly. When the circuit reads a shorted condition, the resistance drops abnormally low, signaling to the control board that the sensor data is invalid and triggering this fault code.

A shorted thermistor circuit is typically caused by physical damage to the wiring harness or the thermistor itself. The cable routing inside the refrigerator compartment can expose wiring to pinch points where doors, drawers, shelving brackets, or panels compress and eventually cut through insulation, creating a direct short. Ice buildup around an improperly positioned thermistor can also damage the sensor or its lead wires over time.

Diagnosing this fault starts with a thorough inspection of the thermistor cable from the sensor tip back to the connector at the control board. Look for any areas where the cable may be pinched, kinked, or where insulation has worn through. A multimeter can be used to measure resistance across the thermistor leads: if the reading is near zero ohms or far below the expected resistance range for the current ambient temperature, the thermistor or its wiring has failed and replacement is required. If the cable and connector check out visually, the thermistor itself has likely shorted internally.