Whirlpool Dryer Moisture Sensor & Thermistor Replacement Guide — What This Part Does
Whirlpool dryers use two different sensors to control drying cycles. The thermistor is a temperature control sensor, usually mounted on the blower housing or exhaust outlet duct, that measures air temperature so the control board can regulate heat. The moisture sensor is a set of metal bars mounted at the lint filter opening or drum front that detect moisture in your clothes and tell the control when laundry is dry enough to end the cycle.
These sensors fail when the thermistor loses its ability to change resistance with temperature (it can go open circuit, short, or drift out of range), or when the moisture sensor bars get coated with fabric softener residue, physically damaged, or suffer harness/connector problems. Both types of failure will throw error codes on newer models or just cause poor drying performance on older machines. Whirlpool uses different diagnostic codes across model families, so the exact fault name depends on your specific dryer platform.
Signs It Needs Replacing
- Dryer won’t heat or cycles cold A failed thermistor prevents the control from reading exhaust temperature, so the dryer may shut off the heating element or run cold to protect itself.
- Auto-dry cycles run too long or won’t shut off Bad moisture sensor bars can’t detect when clothes are dry, so the dryer keeps running or never finishes the cycle.
- Clothes come out damp or cycles end early Contaminated or shorted moisture sensor bars can falsely signal that laundry is dry, stopping the cycle prematurely.
- Error code on display related to sensor or thermistor Newer Whirlpool dryers throw codes when they detect out-of-range thermistor resistance or missing moisture sensor signals.
- Dryer overheats or shuts down mid-cycle A thermistor that reads incorrectly can cause the control to overheat the drum or shut down thinking the air is too hot.
- Timed-dry works but auto-dry does not This points to a moisture sensor problem, since timed cycles don’t rely on the sensor bars to detect dryness.
How to Replace It
- Unplug the dryer from the wall outlet or shut off the circuit breaker to cut all power before starting any work.
- Locate the component you need to replace. For the thermistor, remove the lower front or rear access panel to reach the blower housing or exhaust duct. For moisture sensor bars, open the dryer door and remove screws or clips holding the lint filter housing or front panel to access the sensor area.
- Disconnect the wire harness from the thermistor or moisture sensor by pulling the connector straight off the terminals (do not pull on the wires).
- For thermistor replacement, remove the mounting clip or screw holding the thermistor to the blower housing or duct, then pull the sensor out. For moisture sensor replacement, note the routing of the harness and any retaining clips, then remove the sensor bar assembly from its mounting tabs or screws.
- If testing the thermistor, set your multimeter to ohms (not continuity) and measure resistance across the two terminals. A good Whirlpool thermistor typically reads around 11 to 14.5 kΩ at room temperature (70°F), but this varies by model. If the reading is open, zero, or far outside that range, the thermistor is bad. If testing moisture sensor bars, inspect them for heavy residue buildup, corrosion, or damaged harness wires.
- Install the new thermistor by inserting it into the mounting hole and securing the clip or screw, then reconnect the wire harness. For the moisture sensor, position the new sensor bar assembly in the mounting bracket, route the harness through any clips exactly as the old one was routed, and plug the connector back into the control board or junction.
- Reassemble all panels, lint filter housing, and access covers you removed, making sure all screws and clips are seated.
- Plug the dryer back in or turn the breaker back on, then run a test cycle on auto-dry with a small damp load to verify the sensor is working and the dryer completes the cycle normally.
- If the problem persists after replacing the sensor, check the wiring harness for damage or poor connections at the control board, or consider that the control board itself may have a fault (this is less common but possible).
The Part You Need
| Part | Notes |
|---|---|
| Whirlpool dryer thermistor (outlet/exhaust temperature sensor) | Amazon | Find your model and serial number on the metal tag inside the dryer door opening or on the back panel. Cross-reference that model number with the thermistor part number on the Whirlpool parts diagram or at a parts supplier, because different model families use different sensors. |
| Whirlpool dryer moisture sensor bar assembly (with harness) | Amazon | The moisture sensor usually includes the metal bars and the wiring harness as one assembly. Check your model number (inside the door or on the back) to get the correct sensor and harness kit, since Whirlpool, Maytag, and KitchenAid sister brands share some sensors but not all. |
Related Error Codes
If this part is failing you may also see one of these codes:
- Whirlpool Dryer Af error code
- Whirlpool Dryer F 01 error code
- Whirlpool Dryer F 02 error code
- Whirlpool Dryer F 22 error code
- Whirlpool Dryer F 23 error code
- Whirlpool Dryer F 26 error code
- Whirlpool Dryer F 28 error code
- Whirlpool Dryer F 29 error code
- Whirlpool Dryer F1E1 error code
- Whirlpool Dryer F22 error code
When to Call a Pro
If you’re uncomfortable working with multimeters or accessing internal dryer components, or if you’ve replaced the sensor and the dryer still throws the same error code or fails to dry properly, call a tech. Also consider a pro if you find burned or melted wiring at the sensor connector, since that suggests a bigger electrical fault in the harness or control board. Control board diagnosis and replacement is more involved and usually worth paying for professional troubleshooting if the new sensor didn’t solve the problem.