Dryer will not start or stops with F22 displayed, often shortly after starting a cycle

Safety First: Disconnect power and shut off gas supply (for gas dryers) before working on the unit.

Steps:

• Check venting: Disconnect the exhaust duct from the back of the dryer. Inspect and clean the duct and exterior vent hood. Run the dryer briefly (no load) with the duct disconnected to see if F22 still appears. If it does not, the vent was likely restricted.
• Locate exhaust thermistor: On many Kenmore dryers, the exhaust thermistor is mounted on the blower housing near the thermal fuse and cycling thermostat.
• Inspect and reseat wiring: Ensure the thermistor connector is tight and wires are not pinched or burned.
• Test thermistor: With the dryer unplugged, remove one wire from the thermistor and measure resistance. Compare to manufacturer specs at room temperature. Replace if open, shorted, or far out of range.
• Replace thermistor: Remove mounting screw, swap in new exhaust thermistor, and reconnect wiring.
• Control board: If thermistor and wiring are good and vent is clear, the main control board may misread the sensor and need replacement.