How to Detect a Broken Plumbing Vent

Run water in all of your drains, one at a time. After you shut off each faucet, listen for gurgling noises and sniff for sewer odors. If you detect these odors and noises, you may have a malfunctioning or clogged plumbing vent.

Examine the rubber seal around the exterior of the plumbing vent. This is called the collar boot. It may be cracked or otherwise damaged. Replacing a damaged collar boot will stop the water leak.

Check the interior pipe leading to the plumbing vent. Wait for a rainstorm, then go up to your attic and feel the pipe for water. If you detect water, have the leaky pipe replaced.

Have a friend help you test the plumbing vent for leaks. Equip him with a cellphone and station him in the attic or top floor of your home. Insert a garden hose into the plumbing vent on the roof and turn on the water. Instruct your friend to walk around the home, checking the ceiling for water leakage. If water appears, the plumbing vent is malfunctioning. Your friend should call you immediately if he does see water, so that you can turn off the hose quickly.