Fan howling

Our roof exhaust fan works great except for one thing: in the second speed setting after a few minutes it develops a high pitch howling, siren-like sound. This lasts a couple of minutes then recurs. It is an annoyance, especially at night, but does not affect the fans functionality.

I assumed it was some type of imbalance in the blades or other vibration from the mounting. Anyone have any suggestions for eliminating the noise?

[mjlaupp]

That howling is most likely a dry or bad bearing. Get it replaced while still under warrenty.
Mike

When I read the title of your post "Fan howling" I thought you might be going to comment on yesterday's Rose Bowl game!

Originally Posted by mjlaupp

That howling is most likely a dry or bad bearing. Get it replaced while still under warrenty.
Mike

Thanks - I'll get it done before the warranty expires. Any way to test that diagnosis myself, or will they just have to replace the thing?

[mjlaupp]

I don't know of any way to test this. The motor is on the top of the fan so you can't get to it. If you can feel any abnormal vibration in the fan housing when it is howling, that may confirm the diagnosis. I have had several small motors that would howl, squall, squeak or vibrate from a bad bearing. Most of them spun freely by hand. The only way to check is to replace the motor and try again. I think this motor uses sealed bearings so don't let them put you off by oiling it.
Mike

Originally Posted by Rich_in_Tampa

Our roof exhaust fan works great except for one thing: in the second speed setting after a few minutes it develops a high pitch howling, siren-like sound. This lasts a couple of minutes then recurs. It is an annoyance, especially at night, but does not affect the fans functionality.

I assumed it was some type of imbalance in the blades or other vibration from the mounting. Anyone have any suggestions for eliminating the noise?

Rich,
Is your exhaust fan a "Fantastic Fan?" The unit in our 1998 2619 was. Fantastic Fan is a fantastic company. Call them at 800-521-0298. Explain the problem to them. Chances are they will provide you with the technical support and parts (most likely at no cost) to solve the problem, even if the unit is out of warranty. If it is in warranty, ask for Shelley Dunbar.

Of course, if your unit is still under warranty, and the dealer is located close to you, let them take care of the problem. Just know that Fantastic Fan is a fantastic company that really stands behind its products.

Good luck in solving your problem.