F3
Whirlpool Dryer
Severity: ModerateWhat Does This Error Mean?
The F3 error means the exhaust thermistor in your Whirlpool dryer is reading an abnormal temperature. The thermistor is a sensor that monitors the air temperature leaving the drum. If the reading is too high, too low, or missing, the dryer shuts down to prevent overheating.
Affected Models
- WED5000DW
- WED8000DW
- WED9290FW
- WED4950HW
- Most Whirlpool electric and gas dryers
Common Causes
- The exhaust thermistor sensor has failed and is sending a bad reading
- The exhaust duct is blocked with lint, restricting airflow and causing heat buildup
- The wiring connecting the thermistor to the control board is loose or broken
- The dryer vent hose is kinked or crushed behind the dryer
- A failed heating element is causing extreme temperature swings
How to Fix It
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Unplug the dryer and clean the lint screen thoroughly.
A clogged lint screen reduces airflow and causes the exhaust temperature to spike.
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Check the exhaust duct from the back of the dryer to the outside vent cap.
Remove any lint blockages. A clogged duct is a fire hazard and a very common cause of F3.
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Pull the dryer away from the wall and inspect the vent hose.
Make sure it is not kinked, crushed, or disconnected. Replace it if damaged.
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Locate the exhaust thermistor — it is typically inside the exhaust duct near the back of the drum.
Test it with a multimeter. A working thermistor should show a resistance that changes as temperature changes.
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Replace the thermistor if it tests as failed (open circuit or fixed resistance).
This is one of the most affordable dryer repairs. Parts cost around $20–$60.
When to Call a Professional
If you have cleaned the vent and replaced the thermistor but the error returns, the heating element or control board may be the cause. A technician can use a multimeter to test components accurately. Thermistor replacement is typically affordable — around $20–$60 for the part.
Frequently Asked Questions
What is an exhaust thermistor on a dryer?
It is a small temperature sensor located in the exhaust path. It tells the control board how hot the outgoing air is. If the reading is out of range, the dryer shuts off to prevent a fire or component damage.
Can a clogged vent cause the F3 error?
Yes. A blocked vent traps hot air inside the dryer. The exhaust thermistor detects the extreme heat and triggers F3. Always check and clean the vent before replacing any parts.
How do I clean my dryer vent duct properly?
Disconnect the flexible hose from the back of the dryer. Use a dryer vent brush kit to clear lint from the duct all the way to the outside cap. Also remove and clean the outside vent cap — lint builds up there too. Repeat this cleaning every 1–2 years.