Burnham Alpine HE System making alien spaceship foghorn noise

A couple of things. Has the intake always been positioned in that way? Many condensing boilers will specify they be at the same height as the exhaust, or at least the intake must not be located above the exhaust. The first thing I would do is verify that this is an approved venting termination arrangement with Burnham, because it is highly suspect to me.


Since you mentioned this unit just started doing this recently, I assume it worked without foghorn prior to this. I am also assuming the intake pipe was recently changed, and it used to be located right next to the exhaust at the same level. One possibility is that the intake had been recirculating flue gases for a long time, meaning it would suck in the exhaust, put it back into the boiler and burn again. This is really bad for many reasons, not the least of which being that it can eat away at the "paper" style venturi assembly that many units like this had (recently many of these were changed to a hard plastic)

I dealt with this on a couple of Triangle Tube boilers, what I found is an easy enough way to check without taking the venturi off, is to feel the inside of it. If it is rough at all, and not smooth, I would bet money the backside of it is perforated. A perforated venturi will cause foghorning pretty much without fail. If you have a picture of the parts diagram it should point you in the direction of the venturi


I would also add that not one unit I dealt with that was "foghorning" was burning correctly, it just can't be in the case of a perforated venturi. I hope whichever tech told you it is functioning correctly performed a combustion analysis