How to Fix Resonating Duct Work

You may hear noises resonating from your duct work whenever the furnace or central air unit turns on. Some clicking and popping noises are normal from when the equipment turns on or shuts down. The noises may also come from the cold ducts expanding or contracting due to the differing air temperature that is flowing toward the rooms. You should inspect the duct work to differentiate the normal operating sounds from noises that can be muffled.

1/4 inch sheet metal screws
No. 8 screwdriver
Flashlight
Aluminum tape
3/4 inch hanger screws
Rubber pads

Instructions

- 1
  Locate rattling noises in ducts whenever air is forced through the unit. Take down the section of ducts if the resonating noise shifts and moves. Remove the sheet metal screws with the screwdriver.
- 2
  Shine the flashlight into the duct to see if some foreign object, such as a very small toy or a nail, has fallen into the duct work through floor grating. Remove the object. Replace the one-quarter-inch sheet metal screws.
- 3
  Inspect the entire duct line if your hear hissing noises. Locate the leaking duct where the forced air is making a hissing noise from an open seam. Install new screws if the existing ones are missing. Place aluminum tape over seams to stop hissing noises.
- 4
  Fix duct hangers if the duct is rattling against the joists. Place rubber pads between the duct and the wooden beam. Screw in three-quarter-inch hanger screws into hanger holes to tighten the ducts against the joists.

How Do I Determine If an Air Handler Is Potable Rated?

How to Get a Boiler Out of Latch-Up Mode

Heating & Cooling Repair