Furnace Makes Noise on Startup

Discussion in 'HVAC Heating & Cooling' started by alexjag33, Jan 9, 2009.

  1. alexjag33

    alexjag33 New Member

    Hi all.

    My furnace works OK, but when it starts up, the metal air corridor "expands" and makes a noise like it is inflating. It sounds like a sheet of flexible metal being waved in the wind or something.

    When the furnace shuts off, I hear a quieter "deflate" noise, similar to the previous one.

    Have any of you experienced something similar? How did you resolve it?
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    New England
    It may be what is referred to as oil-canning, where the pressure changes cause the large panels of the duct to pop out or in depending on whether the pressure is going up or down.

    Not a lot you can do about it. Ducts are often made with small creases (often on the diagonals) to add a little more stiffness and lower the probability of that happening. You could also try wrapping them in insulation to muffle the sound, but it may still echo through the ductwork since that won't stop it from happening.

    If the ducts are not well anchored to each other, you may need some screws to hold it together better. If it is isolated to one piece, and you know where it is, you might be able to screw some stiffeners on it to prevent it from oil-canning (assuming that's what it is).

    Hopefully, one of the pros may have some other ideas that may help you.
Similar Threads: Furnace Makes
Forum Title Date
HVAC Heating & Cooling Furnace has no fan relay, which makes it difficult to install HRV Sep 22, 2011
HVAC Heating & Cooling Furnace fan works on AUTO but not on ON Dec 7, 2014
HVAC Heating & Cooling Forced Air Furnace Design, Who Can Do A Good Job? Nov 26, 2014
HVAC Heating & Cooling Run fan only on old gas furnace Nov 25, 2014
HVAC Heating & Cooling Roof Venting Condensing Gas Furnace Oct 21, 2014

Share This Page