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Maintaining TORNADO® Aeration Equipment

TORNADO® aerators are designed to last: Their roller bearings are designed for up to 100,000 hours of service life given proper lubrication.

The TORNADO® line is known for its rugged reliability, and you can even further reduce downtime and lengthen service with these maintenance tips

Fluence’s best-selling line of aerators, the all-stainless-steel TORNADO® family, is as rugged and mechanically reliable as they come. But even with the most robust aeration equipment, maintenance and repairs are sometimes necessary. These simple maintenance tips will help you reduce downtime and lengthen component life.

1. Use Your Eyes and Ears

To properly protect TORNADO® equipment, be aware of unusual noises, excessive vibration, or reduced function. The TORNADO® should run smoothly with no vibrations, rattles, or squeaks. A suction sound when air is drawn through the draft tube is normal, as is an occasional “vortex,” when air is sucked from the surface by the propeller, bypassing the draft tube with a loud slurping noise. Make adjustments if the aerator vortexes more than twice a minute or if a vortex continues for more than 10 seconds. Angling the aerator deeper into the water (at an angle of 45 degrees or greater) will decrease vortexing, and a vortex shield accessory is available.

If you suspect the TORNADO® is not operating as intended, Fluence can help. Turn it off and call our support staff.

2. Motor Maintenance and Amperage Testing

Many TORNADO® aerators are equipped with permanently sealed motors that do not require lubrication. For those that do require lubrication, check the motor manual for both the correct grease to use and the lubrication interval.

Fluence recommends checking the motor amp draw monthly. With the aerator properly moored, mounted, and tilted into the water:

  1. Turn the power on.
  2. Measure the amperage draw at the control box.
  3. Compare with the rated amp draw on the motor nameplate.

If the amperage draw and voltage vary more than 5% from the ratings indicated on the nameplate, contact Fluence with your reading.

3. Lubricating the TORNADO® Aerator

The aerator’s tapered, self-heating roller bearings are designed for up to 100,000 hours of service life given proper lubrication. Lubrication of TORNADO® grease fittings should be scheduled at three-month intervals and after any downtime of more than one month. The TORNADO® Autoluber accessory, however, makes bearing lubrication a yearly job. Contact Fluence to add it to your aerator.

When lubricating bearings, use two shots of Lubrimatic/Witco Corp. N11402 marine corrosion control grease. Use only the specified grease because mixing types of grease can render them ineffective and void your equipment warranty.

4. Keep the Manual Handy

Your TORNADO® manual contains many more tips, so keep it handy for review at maintenance time. Contact Fluence for replacement manuals, which are available in physical or digital versions.

5. Inspections at Six-Month Intervals

Fluence recommends the following inspections twice per year:

  • Inspect Coupling: Check for coupling wear or rubber dust in the coupling area. Realign or replace the flexible sleeve if needed.
  • Inspect Propeller: Check for nicks or pits on the propeller and replace as needed. With the propeller firmly in hand, check for both end play and side play.
  • Inspect Seals: Turn the propeller by hand to make sure it is rotating freely. Remove the propeller and cone, and visually inspect the outer seal to make sure there is no gap between the seal and shaft. Pull on shaft to make sure there is no noticeable end play. If gaps, play, or loose, grinding shaft rotation are detected, remove the seal module and visually check the bearings. Kits are available from Fluence for replacing seal modules or bearings.
  • Tighten Bolts: Tighten all exposed bolts.

Some applications may require more frequent seal inspection.


Keeping parts on the shelf can limit downtime. Consider keeping our maintenance and rebuild kits on hand to streamline the process.

Special Notes

When an aerator is shut down for more than two weeks, the unit should be tipped out of the water to prevent plant and debris buildup inside the draft tube and around the aerator. In lagoons with a high amount of floating rags or plastic, the aerator propeller should be inspected for fouling on a regular basis.

Saltwater immersion of stainless-steel floats requires special maintenance.

For questions, concerns, technical support, or quotes on parts or equipment, contact Fluence by filling out our contact form, calling +1 763 746 9288, or by emailing [email protected]. We’re here to help!

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