Bosch Refrigerator Error Code E2027

The E2027 error code on a Bosch refrigerator indicates a fault with the Tray-NTC sensor. NTC stands for Negative Temperature Coefficient, referring to a thermistor whose electrical resistance decreases as temperature increases. This sensor is positioned to monitor the temperature of a specific tray zone within the refrigerator, often associated with an ice tray, a humidity-controlled drawer, or a temperature-sensitive compartment. The control board uses the resistance reading from this sensor to regulate cooling cycles in that zone. When the board detects a resistance value that falls outside the expected operating range, whether too high, too low, or completely open circuit, it registers the E2027 fault.

The most frequent cause of this error is a failed or degraded NTC thermistor. Over time, thermistors can drift out of calibration or fail entirely due to moisture exposure, physical damage, or age-related degradation. The fault can also originate in the wiring harness connecting the sensor to the control board. A loose connector, corroded terminal, or broken wire will interrupt the resistance signal and trigger the same error. In some cases, the main control board itself may misread a valid signal, though this is less common than sensor or wiring failures.

Diagnosing E2027 typically involves disconnecting the Tray-NTC sensor and measuring its resistance with a multimeter, then comparing the reading against the expected resistance-temperature curve for the specific thermistor used. A reading of open loop or infinite resistance usually confirms a failed sensor. If the sensor tests within spec, the technician should inspect the wiring harness for continuity and check connector integrity before considering control board replacement.