Top 3 Signs of a Clogged Plumbing Vent

March 17th, 2016

Plumbing systems in modern homes depend on plumbing vents to carry away wastewater from dishwashers, toilets, tubs, sinks, and washing machines. When the wastewater can’t flow properly because of a clog in your plumbing vent, it can quickly become a smelly, dirty, and dangerous problem inside your home. If your home’s plumbing vent pipe becomes clogged, you need to call a plumbing professional immediately.


What Are Plumbing Vents?

Plumbing vents (also known as vent stacks) are the upright pipes running inside your home’s walls and out of your roof. They allow air to enter the drainage system and help maintain an even pressure so wastewater can flow away from your home quickly and efficiently. Excessive corrosion, an accumulation of leaves, or even a bird’s nest on top can cause your home’s plumbing vents to become clogged. 


Top 3 Signs Your Plumbing Vent Is Clogged

Air needs to flow freely from your plumbing vent through to your pipes to keep the pressure inside balanced and water moving efficiently. If your plumbing vent is clogged, you’ll experience: 

  • Sputtering and gurgling toilets
  • Slow draining
  • Strong sewage odor

Sputtering and gurgling toilets. When there isn’t enough airflow going through the vent due to a blockage, the pressure inside the plumbing will be greater than the air in your bathroom. When you flush your toilet, the air inside and outside the plumbing will try to equalize. This will cause the water to become agitated and you may hear gurgling or sputtering sounds coming from your toilet.

Slow draining.  Increased drainpipe pressure can prevent water from draining off at an average rate. If your home’s drains are draining slower than usual, an undersized or blocked vent could be the issue. There might also be a clog in the pipe that services the water flow. 

Strong sewage odor. All plumbing drains have a trap where water sits to block sewer gases from entering your home. But when the drain pressure is too high, the water flows out and allows those sewer odors to come in. If you’re smelling sewage in your house, it may be due to a blockage in your plumbing vent. 


How to Unclog a Clogged Plumbing Vent

Option 1: Clear the vent yourself. It will be difficult to find where the clog is exactly located if you’re not a professional, but you can try to unclog the vent pipe yourself before calling a plumber. To check whether the stack itself is clogged from debris, you will need to climb up on your roof. 

Make sure you bring a screwdriver, plumber’s auger, garden hose, and a flashlight with you. If you have a cap on your vent, unscrew it so you can check for any visible debris—clean out as much as you can. If you can’t spot the clog with your flashlight, use your garden hose (preferably with a strong jet setting) to spray water into the pipe to clear the clog. You may need to use the auger to fully clear the pipe. You’ll know the clog is fully removed once water is properly draining again.

Option 2: Have a professional clear the vent (this option is highly recommended). Preventing your plumbing vent from becoming clogged in the first place is preferable—but clogs can still happen. If you suspect you have a clogged plumbing vent and you either can’t find the clog yourself or you don’t feel comfortable going onto your roof, you should call a plumbing professional ASAP to fix the problem for you.


How to Keep Your Plumbing Vent Clear

Taking the time to limit potential future clogs instead of waiting until there’s a problem with your plumbing vent is the best course of action. It will save you money from repairs and keep your home’s plumbing system operating smoothly:


  • Keep debris clear. If you have tree branches hanging over your roof, trim them back so fallen debris doesn’t get stuck in the vent. When wet leaves, branches, and other organic material get stuck inside your pipe vent, it can quickly trap air inside and cause plumbing problems. 
  • Keep out vermin. Small animals like birds, rats, and squirrels are often the cause of plumbing vent clogs. They regularly make small nests inside the stack, get stuck inside pipes, or leave droppings that can cause blockages. 
  • Get the right vent cap. Installing a vent cap can help keep debris and animals from entering your pipes, but it can also be the cause of your blockage. If you live in a cold climate, snow and ice can close your vent opening and stop air from flowing into your plumbing system. Getting high-quality vent caps will avoid malfunctions and ensure proper air ventilation. 
  • Get the right vent pipe size. Not every home has the same plumbing demands. For large homes that have larger plumbing systems, your vent pipe may not be big enough to equalize all of the drains running to it. If your plumbing is experiencing problems properly venting or is draining slowly, you may need to upgrade your stack to a larger vent pipe size. 


When to Contact a Plumber

A blocked or clogged plumbing vent can be difficult to repair by yourself without professional training. In most cases, locating and clearing the blockage includes climbing onto your roof to inspect the stack or even breaking down walls to examine your entire drainage system. Unless you have experience working with these systems, you should hire a professional plumber to properly take care of your clogged plumbing vent.


Call the Experts

If you’re not sure where the clog is located or if you’re nervous about climbing onto your roof to clear the blockage, you should call a professional plumber to fix the problem. Waiting to see whether the clog will clear by itself will most likely cause extensive damage to your plumbing system—and make your entire home smell like sewage. Call the Expert Services- Plumbing, Heating, Air & Electrical today to have one of our professional plumbers come to your home and fix your clogged plumbing vent immediately.