GE Washer Dryer Error Code 15

Error code 15 on a GE washer/dryer combo indicates that the control board has detected an invalid signal from the water temperature thermistor. The thermistor is a resistive temperature sensor whose resistance changes predictably with temperature. The control board monitors this resistance continuously through connector J701. When the board reads a resistance value that falls outside the expected range, or reads no signal at all, it interprets this as either a disconnected sensor, a missing sensor, or a failed sensor, and triggers code 15.

The thermistor plays a critical role in regulating water and drum temperatures during both wash and dry cycles. If the sensor is absent or producing invalid data, the control board cannot safely manage heating elements or water valves, so the machine halts operation to prevent overheating or other damage. The resistance values the board expects are documented in the unit's mini-manual table, which provides specific resistance-to-temperature correlations that must be matched during testing.

Diagnosis begins at connector J701 on the control board. A technician should disconnect the connector and measure the thermistor resistance with a multimeter, then compare that reading against the resistance table in the mini-manual for the corresponding ambient or water temperature. A reading of infinite resistance typically points to a broken wire or fully open thermistor. A reading of zero or near-zero ohms suggests a short in the sensor or wiring. A reading that simply does not align with the expected table values confirms thermistor failure.