GE Dishwasher Error Code F97: Thermistor Probe... | appliancefaults.com

Technical Background:

The F97 error code on a GE dishwasher indicates a problem with the thermistor circuit. The thermistor is a temperature-sensitive resistor that sends a signal to the main control board (MCU) to monitor the water temperature. The MCU uses this information to control the heating element and optimize the wash cycle. The MCU typically reads a voltage drop across the thermistor; a resistance outside the normal range triggers the F97 error.

Symptoms:

The GE dishwasher displays an F97 error code on the control panel and may not start or may stop mid-cycle. The wash cycle might be affected, with improper heating or washing performance.

Possible Causes:

Faulty thermistor
Wiring harness issue (open or short)
Loose connection at the thermistor or control board
Defective main control board (MCU)
Water temperature outside the acceptable range
Software Glitch

Solution:

1

Disconnect power to the dishwasher at the breaker panel.
2

Locate the thermistor, usually at the bottom of the dishwasher near the sump or heater element. You may need a 1/4-inch nut driver to remove a lower access panel.
3

Disconnect the thermistor connector. Visually inspect the connector and wiring for damage.
4

Using a multimeter, measure the resistance of the thermistor. Refer to the service manual for the correct resistance value at room temperature (typically around 50k ohms at 77°F).
5

If the resistance is significantly off or reads open/short, replace the thermistor. Use the proper GE replacement part.
6

If the thermistor tests good, reconnect it and check the wiring harness for continuity using your multimeter. Ensure there are no breaks or shorts in the wires.
7

If the wiring is good and the thermistor is new or tests good, replace the main control board. This requires a 5/16-inch socket for mounting screws.

Safety Warning:

Disconnect power to the dishwasher at the breaker panel before attempting any repairs. Lock Out/Tag Out (LOTO) procedures are recommended to prevent accidental re-energizing of the circuit. Some components may retain a residual electrical charge even after power is disconnected.

Prevention:

Regularly inspect the dishwasher for leaks. Avoid using excessive amounts of detergent, as this can lead to residue buildup that can affect sensor performance. Run a dishwasher cleaner cycle monthly.

Expert Tip:

Some GE dishwashers have a service mode that allows you to monitor the thermistor's real-time temperature readings. To enter service mode, press and hold the Start/Reset button for 5 seconds, then press the following sequence of buttons: High Temp Wash, Energy Save Dry, High Temp Wash, Energy Save Dry. The display will show diagnostic codes and real-time sensor readings. This helps confirm if the thermistor is reporting accurate temperature data.

Frequently Asked Questions

•What is the typical resistance range for a GE dishwasher thermistor at room temperature (70-75°F)?

Typically, a GE dishwasher thermistor should read between 45k ohms and 55k ohms at room temperature (70-75°F).

•How do I access the main control board (MCU) in my GE dishwasher to inspect the wiring and connections?

The main control board is usually located behind the control panel on the door. You will need to remove the outer door panel by removing screws around the perimeter. Be careful when disconnecting wiring harnesses.

•If the thermistor and wiring are good, and the F97 code persists after replacing the main control board, what else could be the cause?

If the thermistor, wiring, and control board have been replaced and the F97 code persists, there may be an intermittent connection issue or a rare software glitch requiring a software update from GE (if available). Reseat all wire harness connections on the MCU and the thermistor again to rule out intermittent connectivity issues.

GE Dishwasher Error Code F97: Thermistor Probe Resistance Check

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance range for a GE dishwasher thermistor at room temperature (70-75°F)?

•How do I access the main control board (MCU) in my GE dishwasher to inspect the wiring and connections?

•If the thermistor and wiring are good, and the F97 code persists after replacing the main control board, what else could be the cause?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: