Whirlpool · Dryer

F3

Exhaust Thermistor Fault

Severity

Medium

The error code F3 on your Whirlpool Dryer indicates a specific system failure categorized as "Exhaust Thermistor Fault". This guide walks you through the most likely causes and the correct repair sequence.

Owner's Summary

Your dryer's temperature sensor is giving incorrect readings, so the machine either won't heat or shuts off too early. This is usually a cheap fix — the sensor itself costs about $15 and takes 30 minutes to replace.

Symptoms

Whirlpool dryer not heating or shutting off too soon, F3 error code

Common Causes

Faulty exhaust thermistor (temperature sensor)
Lint buildup around thermistor sensing area
Damaged wiring to thermistor
Thermal fuse blown causing false reading

How to Fix

1 Test thermistor resistance with a multimeter (typically 10k ohms at room temp)
2 Clean lint from around the thermistor location
3 Inspect wiring harness to thermistor for damage
4 Replace thermistor if resistance is out of specification
5 Check and replace thermal fuse if blown

Tools You'll Need

Multimeter Flashlight

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

Technical Explanation

The CCU reads thermistor resistance to determine exhaust temperature. The thermistor has a Negative Temperature Coefficient — resistance decreases as temperature rises. A failed thermistor reading outside the expected range triggers F3 and disables the heating element relay.

Is It Safe to Keep Using?

Safe to investigate. A dryer that won't heat is not dangerous, but do not ignore blocked exhaust venting as that is a fire hazard.

Technician's Pro Tip

Always check the exhaust duct for lint blockages when servicing any dryer thermistor fault — a clogged vent causes high temperatures that kill thermistors and thermal fuses prematurely. Fix the vent first, then the sensor.

Related Codes

F21 — Whirlpool Washing Machine

Long Drain Time or Drain Pump Fault

High

F20 — Whirlpool Washing Machine

No Water Detected

High

F7E1 — Whirlpool Washing Machine

Motor Speed Sensing Error

High

Frequently Asked Questions

What does error code F3 mean on a Whirlpool Dryer?

Code F3 on a Whirlpool Dryer indicates "Exhaust Thermistor Fault." In practice, the most common trigger is faulty exhaust thermistor (temperature sensor). Severity is rated medium, and typical repair costs range from $5 to $100.

Can I fix F3 myself, or do I need a technician?

Many cases of F3 can be resolved without a technician. The first step to try: test thermistor resistance with a multimeter (typically 10k ohms at room temp). 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 dryer with code F3 showing?

Safe to investigate. A dryer that won't heat is not dangerous, but do not ignore blocked exhaust venting as that is a fire hazard.

How much does it cost to repair F3 on a Whirlpool Dryer?

Repair costs for code F3 typically range from $5 to $100. Thermistor: $10–$30; Thermal fuse: $5–$20; Labor: $50–$100. 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

$5 – $100

Thermistor: $10–$30; Thermal fuse: $5–$20; Labor: $50–$100