Safety first: Disconnect power before accessing internal components. The heater area can be very hot.

Locate the exhaust thermistor: Remove the rear panel. The exhaust thermistor is typically mounted on or near the blower housing or exhaust duct, with two small wires attached.
Check the connector: Ensure the thermistor plug is fully seated and the wires are not broken or pinched.
Test the thermistor: With the dryer unplugged, disconnect the thermistor and measure its resistance with a multimeter. At room temperature, it should read in the range specified in the service manual (commonly around 10k–50k ohms). An infinite (open) reading indicates a failed thermistor.
Inspect wiring: Trace the harness from the thermistor to the control board for cuts, burns, or loose connections. Repair or replace damaged wiring.
Replace the thermistor if open: Remove the mounting screw, swap in the new thermistor, reconnect the wires, reassemble the rear panel, restore power, and test a cycle.

Dryer displays F22 and will not start or stops shortly after starting.

Possible Causes