Whirlpool Dryer F23 Error Code — What It Means
The F23 code on Whirlpool Duet and HE-style dryers signals an outlet thermistor failure. The control board has detected an open circuit, short, or out-of-range reading from the exhaust temperature sensor. This sensor monitors the air leaving the drum and protects against overheating. When the signal falls outside normal parameters, the dryer halts and displays F23.
The fault usually traces to the thermistor itself, a corroded wire terminal, or damaged harness between the sensor and control board. Less often, the control board input has failed. The dryer will not run until the circuit is repaired and the code clears.
Common Causes
- Failed outlet thermistor The exhaust temperature sensor has opened or drifted out of specification and no longer sends a valid resistance signal to the control board.
- Loose or corroded wire connections Terminals at the thermistor or harness connector have oxidized or pulled free, breaking continuity in the sensing circuit.
- Damaged wiring harness The wire run between the outlet thermistor and the control board has been pinched, chafed, or burned, creating an open or intermittent short.
- Faulty main control board The thermistor input circuit on the board has failed even though the sensor and wiring test within range.
Step-by-Step Fix
- Disconnect power at the breaker or unplug the dryer and wait two minutes to reset the control board, then restore power and test a cycle to see if the code returns.
- Remove the top or rear panel to access the exhaust duct area where the outlet thermistor mounts, typically on the blower housing or near the duct exit.
- Inspect the thermistor and wiring for burn marks, loose spade terminals, or visible damage to the harness insulation, and reseat any connectors.
- Measure resistance across the two thermistor leads with an ohmmeter at room temperature, looking for a reading near 10,000 ohms (check your model’s service sheet for the exact specification).
- Check harness continuity from each thermistor wire back to the control board P4 connector, confirming no opens or shorts to ground.
- Replace the outlet thermistor if the resistance is out of range or the sensor shows physical damage, then clear the code and test.
- Replace the main control board if the thermistor and wiring both test good but the F23 code persists after reassembly.
Parts Often Needed
| Part | Notes |
|---|---|
| Outlet thermistor (exhaust temperature sensor) | Amazon | Match your dryer model number. Most Duet sensors are plug-in style with two-wire spade connectors. |
| Dryer wiring harness (thermistor to control) | Amazon | Order the section that connects the blower housing to the control board if individual wires are damaged. |
| Main control board (electronic control) | Amazon | Required only if sensor and wiring test good. Verify your model and board part number before ordering. |
When to Call a Pro
Call a technician if you are uncomfortable working inside the dryer cabinet, if voltage measurements at the control board are required, or if the fault returns after you have replaced the thermistor and verified wiring continuity. A qualified service provider has the model-specific resistance tables and can isolate board-level failures without replacing parts by trial. If your dryer is still under warranty or a service plan, professional diagnosis is usually covered and safer than self-repair.