U-Line Ice Maker Error Code L Evap T Open

The L Evap T Open error code on a U-Line ice maker indicates that the left evaporator thermistor circuit is reading as open, meaning the control board is receiving no signal from that sensor. The evaporator thermistor is a temperature-sensing resistor (thermistor) mounted on or near the evaporator coil. Its job is to continuously report evaporator temperature to the control board so the unit can regulate refrigeration cycles and harvest timing. When the circuit is open, the board cannot confirm whether the evaporator is cooling properly, and it triggers this fault to prevent the unit from operating in an uncontrolled state.

An open circuit in a thermistor can result from a broken wire, a corroded or disconnected connector, or a failed thermistor itself. Unlike a short circuit, which forces resistance to near zero, an open circuit means resistance is effectively infinite, as if the circuit has been completely interrupted. This is distinct from a reading that is simply out of range and typically points to a physical break somewhere in the wiring harness or at the sensor itself rather than a refrigeration system problem.

Diagnosis should begin at the thermistor connector. Inspect the connector for corrosion, bent pins, or loose seating and reseat it firmly. If the connection is intact, use a multimeter to check continuity and resistance across the thermistor leads. A thermistor with an open circuit will show no continuity at all. If the thermistor tests as open, it requires replacement. Also trace the wiring harness from the connector back toward the control board to check for any damaged or pinched wire segments.