"Exhaust Fan" fan impeller: Check the fan wheel operation is normal, but if you have deformed curved plate is stuck, then you should adjust the gap between the fan wheel and the arcuate plate as soon as possible or replace the exhaust fan fan impeller. Motor bearing wear: motor bearing wear is likely to cause the motor stator and rotor collide with each other, which appears stuck phenomenon, this time just to replace what bearing can solve the problem. Motor starting capacitor damage: Check the motor start capacitor, if damaged, it should replace the motor starting capacitor.