How Do You Lubricate a Furnace Blower Motor?

To lubricate a furnace blower motor, remove the oil caps to expose the bearings and apply just two to three drops of a lightweight machine oil. Not all furnaces require lubrication, so check the furnace's owner's manual for specific instructions on regular maintenance.

To lubricate the motor and shaft bearings on a furnace:

  1. Turn off the power
  2. Ensure the power to the furnace is off at the main electrical panel before disassembling the unit.

  3. Access the furnace blower
  4. Remove the blower and motor unit from the furnace assembly by unscrewing it from the wall and the pilot assembly.

  5. Clean the caps
  6. Before lubricating the bearings, thoroughly clean around the caps that are covering the bearings, and then remove the caps to access the bearings.

  7. Lubricate the bearings
  8. Older furnaces typically have two blower shaft bearings and two motor bearings. Lubricate these bearings once a year for annual maintenance and optimal performance. Use a lightweight machine oil, as other oil types are flammable and can be dangerous in a furnace. Do not over-lubricate the bearings; just two or three drops of the oil should be sufficient for each bearing.

  9. Reassemble the unit
  10. Reattach the cap and re-install the blower and motor unit inside of the furnace. Perform other regular maintenance tasks before turning the power back on.