How to Check Furnace Ducts for Blockage

If one of your furnace ducts becomes blocked, you'll notice it -- any room fed air via the blocked duct won't heat or cool sufficiently, leaving you with a too-cold room in winter even with the thermostat turned up. Not only is it uncomfortable, it wastes energy and money on your heating bill. If you suspect one or more of your home's ducts are blocked, you may be able to at least partially solve the problem yourself with quick check.

Screwdriver
Flashlight

Instructions

- 1
  Remove the vent to the room where the blockage is suspected with a screwdriver. There are usually two to four Phillips-head screws holding a vent in place. If you can't find the vent, look behind furniture and along the base of the ceiling.
- 2
  Look inside the duct with a flashlight. It should be completely empty and clear as far as you can see. If you see anything inside the duct, remove it if possible.
- 3
  Replace the vent.
- 4
  Check the ducts in the attic or crawl space if possible. Look for kinks or crushed sections in the ducts, which cause blockage.
- 5
  Adjust any blocked ducts carefully to allow the air to flow through, taking care not to loosen any joints or connections.

DIY Bathtub Couch

How to Have Cross Ventilation in a Single-Window Room

Ventilation