GE Dishwasher Error Code F59

F59 on a GE dishwasher means the control board has detected a low out-of-range reading from the dry heater thermistor, which is the temperature sensor for the drying heater. The board is not receiving a signal within the expected resistance range, so it stops the cycle to prevent the heater from running without proper temperature monitoring. The cause can be a loose connector, damaged wiring, or a failed thermistor.

The dishwasher will typically stop the cycle when F59 is active, so the drying heater is not operating without temperature feedback. Running the machine repeatedly while the error is present is not recommended because the drying function will not work correctly and the underlying electrical fault should be resolved before continued use. The dishwasher is not a fire or flood hazard in this state, but normal operation is compromised until the thermistor circuit is repaired.

A faulty control board can produce F59, but it is the least likely cause and should only be considered after the thermistor, its connector, and the full wiring harness have been tested and confirmed good. Replacing a control board on a GE dishwasher typically costs $150 to $300 for the part alone, so ruling out the thermistor circuit first is essential before committing to that repair.

Start by unplugging the dishwasher and locating the dry heater thermistor harness connector. Disconnect and firmly reseat the connector, then check each terminal inside the housing for bending or corrosion. If the connector and wiring look intact, use a multimeter to test the thermistor's resistance; a reading of infinite resistance means the thermistor has failed open and needs to be replaced. If resistance reads correctly, inspect the wiring harness along its full length for damage before suspecting the control board.

If the fix is a reseated connector or a straightened terminal, there is no parts cost and only your time is involved. A replacement dry heater thermistor typically costs between $15 and $40 for the part. If a technician is needed, expect a service call fee plus labor, which commonly brings the total to $100 to $200 depending on your area and the specific GE model.