When most vacuum cleaners are in operation, the device will emit a steady, low-pitched noise. This noise may change in tone or volume as dirt or debris is suctioned into the vacuum cleaner but remains fairly constant during use. However, if there is an airflow blockage or the vacuum cleaner has not been set to the correct height for the type of floor or carpet being cleaned, there may be a high-pitched noise instead. Fixing this issue should be relatively simple to do.
Turn off and unplug the vacuum cleaner. Step on the handle release pedal, usually located on the base of the unit, and lower the handle.
Turn the vacuum cleaner over and inspect the brush roller and nozzle for any obstructions. Remove long strings or hair that may have caught in the brush with a pair of scissors. Inspect the nozzle and clean away anything that may be blocking the airflow.
Set the vacuum cleaner back up and disconnect the hose from the base of the unit. Look inside for any possible obstructions and clear them as needed. Other hose connection points may include the diverter on the lower back of the unit and the foot hose. Remove any screws present then loosen and straighten the hose to look for and remove any obstructions.
Inspect the dirt container or dust bag for items that may be blocking the airflow. Remove the dust bag or dirt container and empty the container or replace the dust bag. Look at the nozzle connection point for any possible obstructions and clear them as needed.
Clean the vacuum filter by tapping it over a waste bin and rinse it off if marked "Washable." Air-dry the filter completely before reinstalling it into the vacuum cleaner.
Look at the height adjustment knob and turn it to the correct setting for the surface being cleaned. Low settings are best for bare floors or delicate carpets, medium settings are best for most carpet surfaces, and high settings are appropriate for plush or high-pile carpet surfaces.