So Your Toilet Vent Clogged: Identifying, Common Causes and How to Fix a Potentially Messy and Smelly Situation

AllClear 9:54 pm

So Your Toilet Vent Clogged: Identifying, Common Causes and How to Fix a Potentially Messy and Smelly Situation

As a homeowner, you’re likely to become frustrated when you notice that your toilet keeps getting clogged, and you need emergency plumbing solutions. When you think of a clogged toilet, the first thought that comes to mind is probably an issue with the drainage pipes. What you might not realize is there is another part that gets blocked too, and it’s one that’s equally as important. Sewer vents get found on the roof of your home, and they let gases flee your sewer system. They also regulate air flow and allow waste to flow freely. So, if they get blocked, your system won’t drain correctly, and you’ve got yourself a problem that could end up being more than a smelly mess.

(Note: this is different from the vent fan. If you are having issues with smells and think it might be your vent fan, check out this really helpful guide on correctly installing bathroom fans.)

How to clear a vent clog in a toilet

Identifying a Blocked Toilet Vent

It’s a possibility that your toilet vent clogged days or weeks ago, but it’s gone undiagnosed because the signs are similar to that of a blocked drain pipe. You might try a handful of home remedies to fix what you think is a clogged pipe, but it never works. It’s important to seek assistance from a professional plumber if you still see the following symptoms after your DIY fix.

  • Bubbling Noises: Gurgling and bubbling sounds occur when air leaves the drain. It should flow up through the sewer vent, but if it’s clogged, it has nowhere to escape but to move through the pipes. It’s possible that you could hear bubbling noises from the tub after you’ve flushed your toilet, and that’s an indication that they share the same pipe.
  • Slowness: If you notice one drain in your home is slower than the others, it’s indicative of a blocked drain. However, if all drains are slow, it’s likely that your toilet vent is clogged, and you should seek a plumber’s assistance.
  • Sewer Odors: Unfortunately, sewage odors don’t smell like flowers, and if you notice the distinct smell, there is a problem. If there is no backup or spillage, the odor is likely the air leaving the drains.

Common Causes of Clogged Sewage Vents

While it might feel like your toilet clogged for no reason, there’s always a cause that gets uncovered after a bit of investigation. Many different reasons could cause your vent to get blocked, but here are some common ones.

  • Heavy Snow: While we don’t often have to worry about this in South Carolina, it’s possible that a build-up of heavy snow on your roof could have blocked your toilet vent. The issue is mostly known to occur on flat roofs because the snow doesn’t drain properly. It can also happen after a heavy snowstorm that causes a few feet of snow to build up on the roof.
  • Debris and Dirt Build-Up: The angle that your vent gets positioned at is critical because it helps to prevent leaves and debris from building up inside of it. If the vent isn’t at the right angle, or the cap has somehow gotten damaged, debris could build up and have you see your toilet clogged for no reason.
  • Sewer Clogs: It’s possible that there is a clog where your sewer line meets your toilet vent, and the block keeps air from traveling up to the vent. Many times the clogs happen because items such as wet wipes, feminine hygiene products, paper towels, and more get flushed when they shouldn’t be.

toilet vent clogged

The Toilet Vent Clogged: How to Fix It

You now know some of the reasons the toilet gets clogged with the help of our guide. So, the next step on your list is to repair your clogged vent, so you don’t get stuck with unpleasant and possibly harmful smells. As professionals, we recommended that you enlist the help of qualified plumbers who are trained to take care of and fix all of your plumbing issues. That is how the problem would commonly get resolved. If you want to try on your own, you need a garden hose, adjustable ladder, and at least a 20-foot sewer auger for home resolution.

toilet vent clogged

  1. Place an adjustable ladder against the side of your home and ensure it gets secured safely with ropes and fasteners before you climb up. You should also have a spotter reinforce the ladder as you’re climbing it.
  2. Climb onto your roof and then seek out the opening of the vent. Typically, it gets found above the primary bathroom. You should open the cap to inspect the vent and pull out any type of debris that you can reach. It’s possible that birds and other small animals have crawled inside and they can block airflow. That’s one reason why your toilet keeps getting clogged.
  3. Using a garden house with a jet setting or nozzle, spray the water into the opening of the vent. It might be enough to clear them, but if it isn’t, water is going to spill from the opening, and you should contact a plumber for a more aggressive approach.
  4. Push the head of a sewer auger into the toilet vent until you can’t push against the block anymore. You should have at least a 20-foot auger, and it needs to reach from the roof to your sewer.
  5. Next you should turn the device through the obstruction causing the block. Water is going to drain once it’s been cleared, and you can then remove the auger and clean off the leaves and debris.
  6. Make sure that you spray some water into the sewer vent to confirm that you’ve cleared the clogged. It’s possible that the blockage flowed halfway through the pipes, just to get blocked in a different place. If the water overflows again, go in with the auger once more or contact a plumber.

Managing any type of sewage clog or plumbing issue in your home is delicate work that should get handled by our trained plumbers. If you have suspicions that your toilet vent is clogged, contact us today so we can provide you with efficient plumbing solutions. By ensuring that you’re letting a certified plumber fix your issue promptly, you’re avoiding the possibility of sewage backup and unpleasant smells filling your home.

Article Author: Anja Smith

Managing Partner

Anja Smith is the author behind the All Clear Plumbing blog. She also writes regularly for Plumber Magazine,, and on Medium