Our furnace has been making a really loud buzzing sound, that seems like a transformer sound, but it isn't coming from the body of the furnace where the motor is, but from the metal chute surrounding the chimney. Any idea what the issue might be and whether it's something we might be able to fix ourselves?

Thank you so much!

Perhaps a motorized damper or, if the flue is rather long, a secondary draft inducer. Do you hear it continuously, or just when the furnace is running?

Ever hear of Winter Bees? They love chimneys :)

Pull part of the flue off and try to track down the sound.

Perhaps a motorized damper or, if the flue is rather long, a secondary draft inducer. Do you hear it continuously, or just when the furnace is running?
It's a continuous sound, not just when the furnace is running. The flue isn't that long, just from the basement to the roof of our ranch home. If there was an issue with the damper, would it actually buzz continuously?

I guess I'm most concerned with whether this could be something serious. Since the furnace seems to be heating just fine, and money's pretty tight for us these days, I'd rather not call someone in to fix it if there's no chance of it being dangerous. We can live with the noise, but of course I don't want to put our family in any danger. Thank you again!

Elizabeth

For the short term, invest in a CO detector if you don't have one already.