Make sure the dirt canister seals are clean and tight. Commonly, they get caked with dust over time and don't seal well.
The HEPA filter could be part of it, but the vacuum shouldn't make a cloud of dust without it (the HEPA filter) in place. The HEPA filter removes particles that are microns in size; we're talking dust mites, smoke, pet dander, etc. You may have a dirty or missing filter before the HEPA.
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Make sure the dirt canister seals are clean and tight. Commonly, they get caked with dust over time and don't seal well.
The HEPA filter could be part of it, but the vacuum shouldn't make a cloud of dust without it (the HEPA filter) in place. The HEPA filter removes particles that are microns in size; we're talking dust mites, smoke, pet dander, etc. You may have a dirty or missing filter before the HEPA.