GE Dishwasher F97 Error Code: High-Limit Thermostat... | appliancefaults.com

Technical Background:

The MCU (Main Control Unit) monitors the temperature via the thermistor and activates the heating element. If the high-limit thermostat trips due to excessive temperature, it breaks the circuit to the heating element and signals the MCU, resulting in the F97 error. The thermostat is designed to protect the dishwasher from overheating. The voltage path typically involves 120V AC to the heating element through the thermostat.

Symptoms:

The dishwasher displays an F97 error code. The dishwasher may not heat the water properly, or the cycle may stop prematurely.

Possible Causes:

Overheating due to heating element malfunction
Faulty high-limit thermostat
Blocked circulation pump restricting water flow
Defective thermistor providing inaccurate temperature readings
Control board failure
Excessive mineral buildup on the heating element

Solution:

1

Disconnect power to the dishwasher at the breaker panel. Verify zero voltage at the dishwasher's power supply using a multimeter.
2

Locate the high-limit thermostat, typically near the heating element or sump area. It is often a small, round component with two wires attached.
3

Inspect the thermostat for any signs of damage, such as burns or cracks. Check the wiring connections for looseness or corrosion.
4

Use a multimeter to test the thermostat for continuity. A normally closed thermostat should show continuity. If open, it has tripped.
5

If the thermostat has a reset button, press it firmly. If there is no reset button, it may need replacement.
6

Reconnect power to the dishwasher and run a short test cycle. Monitor for proper heating and water circulation.
7

If the problem persists, consider replacing the heating element, circulation pump, or control board after further diagnostics.

Safety Warning:

Always disconnect power to the dishwasher before performing any repairs. Lockout/Tagout (LOTO) procedures should be followed to prevent accidental re-energization. Be aware of 120V AC voltage present at the heating element and control board. Wear appropriate safety gear, including insulated gloves.

Prevention:

Regularly clean the dishwasher filter to prevent clogs. Use a dishwasher cleaner monthly to remove mineral buildup. Check spray arms for obstructions and ensure proper water pressure to the dishwasher.

Expert Tip:

Many GE dishwashers have a service mode that allows for testing individual components. To access service mode, press and hold the 'Start' and 'Heated Dry' buttons simultaneously for 5 seconds. Consult the service manual for specific test procedures.

Frequently Asked Questions

•How do I test the thermistor?

Disconnect the thermistor and use a multimeter to measure its resistance. Compare the reading to the thermistor's resistance chart (typically found in the service manual) at a known temperature. A significant deviation indicates a faulty thermistor.

•Where can I find the service manual for my GE dishwasher?

You can often find the service manual online by searching for your dishwasher's model number followed by 'service manual' or 'technical sheet.' GE also provides service manuals on their website and through authorized parts distributors.

•What is the typical resistance range for the heating element?

The resistance of the heating element typically ranges from 10 to 30 ohms. Measure the resistance with a multimeter after disconnecting power to the dishwasher and disconnecting the wires from the element.

GE Dishwasher F97 Error Code: High-Limit Thermostat Reset Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I test the thermistor?

•Where can I find the service manual for my GE dishwasher?

•What is the typical resistance range for the heating element?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: