GE Washer Error Code E66

E66 on a GE washer means the control board has detected an open circuit in the water temperature sensor circuit. This means the board is receiving no signal from the thermistor, which is the component that measures water temperature. The cause is typically a failed thermistor, a disconnected wiring connector, or damaged wiring between the sensor and the board.

Running the washer while E66 is active is not recommended. Without a functioning temperature sensor, the control board cannot accurately regulate water temperature, which could result in improper wash performance or overheating depending on how the machine defaults. It is best to resolve the error before continuing use.

A reset may temporarily clear the E66 code, but the error will return if the underlying fault is still present. Resetting the washer does not repair a broken thermistor, damaged wire, or faulty board. The code should be treated as an indicator to diagnose and fix the root cause rather than simply cleared and ignored.

Many E66 repairs are within reach for a technically inclined DIYer. Start by checking for loose or disconnected connectors at the thermistor and at the control board. If connectors are secure, use a multimeter to test the thermistor for continuity and resistance. Replacing a thermistor is generally a straightforward repair involving unplugging the connector and swapping the sensor.

If the fix is simply reseating a connector, there is no parts cost involved. Replacing the thermistor typically costs between $15 and $50 for the part. If the control board requires replacement, parts alone can range from $100 to $300 or more, and professional labor will add to the total.