This situation can try to listen to the wind, to open the hood's wind volume to the highest, that is, open the hood to the maximum, and then listen carefully to the sound, if the wind sound only a "whirring" sound, that is normal, if there is a sound, the situation is the outlet is blocked. Other ways to deal with: 1, this situation is rare, generally does not appear, if the wind wheel itself is damaged, it may be bearing damage, such a case need to replace the wind wheel. 2, you can try the suction. The same is to open the hood's wind volume to the maximum, and then use a piece of newspaper to stick firmly in the wind, if you see the newspaper can be sucked, and then pull the hood's exhaust pipe, this situation can be concluded, is the hood's exhaust pipe is blocked. If the airflow is almost the same in both cases, then it is the quality of the range hood. If the motor is damaged, in this case we should let the smoker stopped working, when it does not have a buzzing sound, this situation is easy to judge. Just need to light a lighter or a candle, turn on the motor, check, is it sucking or blowing, if the hood blowing is proof that the motor is reversed, this case is sucking proves that it is the motor power is too small, deformation of the wind blades, exhaust pipe is too long.