Humming Noise on Mt. Vernon AE

Boy, that this beast put out some heat! Anyway, while running the unit, I hear a humming almost like a vibrating sound in the background. Dealer says its just air in the unit? Sounds like hmm, hmm, hmm every few seconds or so. Not very loud but noticeable nonetheless. Thoughts?

could be when the auger is turning to feed pellets.

Can you tell which side the hum is coming from?

If you hear the hum on the left side facing the stove I would bet it is the convection fan.

I had this problem and it eventually got worse. The dealer replaced it and I have not had further problems with it.

I agree...try turning the heat setting (pellet feed) higher or lower and see if the time between "hums" increases or decreases.

Is this a brand new unit? If not, could be convection fan w/ some dust buildup on the fan blades causing it to be slightly out of balance and causing a resonance.

Check the settings is the fan on quiet or std setting