GE · Dishwasher

F4

Open Thermistor

Severity

Medium

When a GE Dishwasher shows F4 on its display, the internal diagnostic system has flagged a condition known as "Open Thermistor". Most repairs for this code are straightforward and can be completed at home.

Owner's Summary

The temperature sensor in your GE dishwasher has failed in an open circuit — meaning no reading is getting to the control board. The board defaults to running the cycle without heat to avoid overheating. Replacing the inexpensive thermistor is usually the fix.

Symptoms

GE dishwasher not heating, running cold cycles, F4 displayed

Common Causes

Open circuit NTC thermistor
Thermistor connector disconnected
Wiring harness break to thermistor
PCB ADC circuit failure

How to Fix

1 Test thermistor resistance — open circuit means infinite resistance
2 Check thermistor connector is firmly seated
3 Inspect wiring harness continuity to thermistor
4 Replace thermistor if open circuit confirmed
5 Replace PCB if thermistor and wiring are good

Tools You'll Need

Multimeter Electrical Contact Cleaner Flashlight

These are simple, low-risk fixes most homeowners can do with tools already in a basic toolbox.

Technical Explanation

An open thermistor presents infinite resistance to the PCB voltage divider circuit, causing the ADC input to read maximum voltage — interpreted as an extremely cold temperature. F4 is posted when this condition is detected at cycle start, and the heater is disabled as a safety precaution.

Is It Safe to Keep Using?

No immediate safety risk. Cold cycles will still run. Fix within a week.

Technician's Pro Tip

The thermistor connector on GE dishwashers is inside the door near the latch area. Open the door and look for a small 2-wire connector — corrosion on these pins is a very common cause of open-circuit readings even when the thermistor itself is fine.

Related Codes

E11 — GE Washing Machine

Water Fill Issue

High

E21 — GE Washing Machine

Slow Drain or Drain Fault

High

E31 — GE Washing Machine

Pressure Sensor Fault

Medium

Frequently Asked Questions

What does error code F4 mean on a GE Dishwasher?

Code F4 on a GE Dishwasher indicates "Open Thermistor." In practice, the most common trigger is open circuit NTC thermistor. Severity is rated medium, and typical repair costs range from $15 to $200.

Can I fix F4 myself, or do I need a technician?

Many cases of F4 can be resolved without a technician. The first step to try: test thermistor resistance — open circuit means infinite resistance. If that doesn't clear the code, work through the remaining steps in the "How to Fix" section above before assuming a part needs replacing.

Is it safe to keep using my dishwasher with code F4 showing?

No immediate safety risk. Cold cycles will still run. Fix within a week.

How much does it cost to repair F4 on a GE Dishwasher?

Repair costs for code F4 typically range from $15 to $200. Thermistor: $15–$40; PCB: $80–$200. Costs on the low end usually reflect a DIY fix with no parts required, while the high end reflects a part replacement plus professional labor.

Estimated Repair Cost USD

$15 – $200

Thermistor: $15–$40; PCB: $80–$200