What do I do if my blower does not turn?


The first step is to examine the driver and see if the driver components such as the motor or engine are in proper working condition. If the driver is operational, you need to turn off, or de-energize, the system and lock out the power supply.

Follow these steps to open up the inside of the blower:

  • Turn off the system and lock out the power supply.
  • Remove any filters, silencers or fittings that block access to the inlet and discharge.
  • Remove belts or coupling guards so you can turn the unit shaft.


Once it is opened up, you can check inside the unit and look for accumulated debris. Plastic, cement, rust and other assorted debris can build up and create an obstruction inside the blower.

Remove any accumulated debris you find. In some cases, you may have to take the unit apart and clean the affected components with solvent.

Rotate the shaft back and forth to determine if there is any motion. If you cannot do a full rotation, you may need to remove the shaft for repairs. Never use a pipe wrench to rotate the shaft under any circumstances. It could bend the shaft and lead to costly repairs. A strap wrench is a much better option.

If the unit is simply rusty, you can apply a PB Penetrating Catalyst to it. Spray a liberal amount over the surface of the headplates, impellers and other internal components. Allow the solution to remain on the components anywhere from a few minutes to a few hours depending on the severity of the rust.

Once the right amount of time has passed, go back and rotate the shaft back and forth again. If you have a Roots unit that features a locknut on the timing gearbox, simply drain the oil out of the gearbox housing and remove the housing cover. Take a socket and a ¾ inch or 1 inch ratchet and use these on the drive motor timing gear nut to rock the unit back and forth in a clockwise direction. Be careful not to loosen the lock nut. Keeping trying to rotate the unit until it turns freely.

Replace the gearbox cover and refill the unit with the amount and type of oil specified in your owner's manual. Then, reassemble the drive and put the piping back into place. Your unit is ready to be energized again. If everything sounds right when it is energized, operate the unit at minimum load for five minutes to ensure proper turning and performance.

If the unit has built up too much internal rust and cannot be made to turn freely with this method, it must be torn down. Each component must be cleaned through sand blasting to remove the rust and then it can be reassembled. If you need to tear down and reassemble the unit, it is a good idea to replace all of your existing bearings, seals and gaskets with newer ones.