Dryer displays F20 and will not start or stops mid-cycle, often on Kenmore Elite steam dryers

Safety First: Unplug the dryer and shut off gas (for gas models) before service.

Steps:

• Clean lint path: Remove the lint screen and clean it thoroughly. Vacuum the lint chute and check the exhaust duct for heavy lint buildup that could cause overheating.
• Access the front bulkhead: Remove the top panel, then the front panel as needed to reach the inlet thermistor (usually mounted on the blower housing or front bulkhead).
• Inspect wiring: Check the thermistor connector and wiring harness for loose connections, burns, or damage. Reseat the connector.
• Test thermistor: Disconnect the thermistor and measure resistance with a multimeter. At room temperature (~70°F / 21°C), most Kenmore thermistors read around 10k ohms (check model-specific specs). Infinite or near-zero resistance indicates failure.
• Replace thermistor: If readings are out of range, remove the mounting screw or clip and install a new OEM inlet thermistor.
• Control board check: If a known-good thermistor and wiring are present but F20 persists, the main control board temperature circuit may be defective and require replacement.