How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Bryan Your Own Question
Bryan, Home Appliance Technician
Category: Appliance
Satisfied Customers: 12156
Experience:  15 yrs. experience as a certified appliance technician.
Type Your Appliance Question Here...
Bryan is online now
A new question is answered every 9 seconds

I have a Nutone Central Vac Model# XXXXX Advantage Series

Resolved Question:

I have a Nutone Central Vac Model# XXXXX Advantage Series Power Unit, about 6 years old. Noticed that over time a black powdery substance on the wall on the left side of the unit {unit mounted in a corner and exhausted outside} that appears to be coming from the vac unit. Seems almost like a fine graphite type substance. It has gotten worse over time, started about 2 years ago. Unit works fine but concerned about health issues with this. Any thoughts appreciated ~ thank you!
Submitted: 5 years ago.
Category: Appliance
Expert:  Bryan replied 5 years ago.

Hi,Welcome to Just Answer, My name is XXXXX XXXXX forward to helping you today.


this type of black powdery substance comes from the Vac motor itself, the bearing may be going in the motor, when the motor is running it will trough the black substance from the motor casing. the motor bearings are desinagrating slowly.

I would have a tech out to check the motor, these can sometimes become a fire hazard it the motor seizes, its best to have it checked. hope this helps, thanks Bryan
Bryan and other Appliance Specialists are ready to help you