F09Warning

Speed Queen Dishwasher F09 Error Code

The thermistor (temperature sensor) has failed open or shorted.

Common causes

  • Defective thermistor
  • Damaged wiring
  • Control board fault

How to fix it

  1. Unplug dishwasher for 1 minute to reset control.
  2. Check resistance of thermistor (should be ~10k ohms at room temp).
  3. Inspect wiring for breaks or corrosion.
⚠ When to call a pro: If resistance is out of range, replace thermistor or call technician.

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Always unplug the appliance (and turn off the water for washers/dishwashers) before inspecting. These guides are for information only and are not a substitute for a professional repair.