Hi. I just joined the forum. I had a Mt. Vernon AE freestanding installed a few weeks ago by a dealer. I'm in central New Jersey. The unit it catty corner in a family room with a 2-level ceiling. There is an outside air kit, a few inches from the floor. Directly above the OAK, about 7 feet up is the exhaust vent. Since the unit was installed it makes a very loud noise whenever it's running and it's almost constant. It sounds like a vacuum cleaner running or like a high pitched version of the sound when you blow across a bottle top. It gets louder and higher pitched as the flame gets larger and decreases pitch and a bit in volume as the flame decreases. Basically, as the flame ebbs and flows the noise matches it. I think it's the air intake motor or blower and it doesn't seem to be the blower or motor that expels hot air into the room. From the exterior if you listen directly at the OAK intake, you can very clearly hear the sound I'm referencing. I'm running hardwood pellets and typically run it on auto but have also tried manual. I've tried increasing and decreasing the flame but those changes make no difference. I'm planning to have the dealer/installer back out to check it out. Any ideas what the sound could be? Does this sound like normal behavior? The noise is loud enough to be heard in other rooms. Could this be an air leak? Defective motor? Bad install? It's a brand new unit. Thanks for any help you can offer!