Troubleshooting clogged dust collector filters

Photo By Oneida Air Systems

If the filter on your dust collector clogs quickly – it collects as much dust and debris as you find in the drum – it’s likely there’s an air leak somewhere below the cyclone.

To work properly, a cyclonic dust collector system needs the dust collection drum to be under negative pressure, in other words, in a vacuum. The centrifugal force of the cyclonic action pushes dust particles to the outer edges of the cyclone where they spiral down toward the collection drum. The clean air from the center of the spiral is pulled back up and sent through the filter.

When the cyclonic system isn’t perfectly sealed, outside air is able to leak into the system. That air disrupts the cyclonic flow and creates turbulence. Dust particles end up in the center of the cyclone, where they get pulled up and sent to the filter.

It doesn’t take long for the filter to become clogged and for the system to become ineffective.

How to find an air leak
Check all connection points between the housing and the cyclone, as well as the bottom of the cyclone and the drum. We recommend using the smoke from burning incense to see where air is moving around your system. Simply light an incense stick while the system is running and move the stick:

• Around the perimeter of the cyclone where it connects to hose, ductwork, or directly to the drum lid
• Around the perimeter of where the drum lid meets the drum
• Damaged spots on fiberboard drums
• Any other connection points in your setup

If you see the incense smoke being drawn into the system, you’ve found an air leak that needs to be sealed. Keep looking for other leaks, including damaged spots on fiberboard drums.

How to fix an air leak
Depending on your system and the location of the air leak, you may need to:

• Tighten or reposition hose clamps
• Replace a neoprene gasket
• Add tape to rigid ductwork
• Apply silicone caulk


Contact a reputable dust collection supplier for additional questions.

Source: Oneida Air Systems. For information call 800-732-4065 or visit

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