Diagnosing And Solving Toilet Venting Problems

20 July 2015
 Categories: , Articles


Notice any foul odors coming from your toilet lately? Or perhaps you've noticed that your toilet is flushing and refilling sluggishly? If you haven't found any clogs in your toilet's drain line, then chances are you're dealing with a problem with the toilet's venting system. Venting problems can cause a number of issues, affecting your toilet and the rest of your home's drainage system.

The following offers some helpful tips on how to diagnose and solve this problem.

How the Venting System Works

To keep sewer gases from entering your home, your home's plumbing features a "U" shaped or "P" shaped trap between the toilet and the main waste line. The trap holds a small amount of water inside as a barrier against sewer gas seepage.

As water flows through the pipe, it also pushes the air in the trap ahead of the water flowing through the drain line. This creates an air pressure imbalance that slows down the toilet's draining action and overall performance.

To prevent this problem from happening, there are a series of vents attached to the main waste line. These vents allow the trapped air to escape outdoors, and they also let outdoor air enter the line. This helps prevent a vacuum from forming in the line, which could rob the toilet of its water and allow sewer gases to enter your home.

Common Signs of Poorly Vented Drain Lines

It's not uncommon for the vent system to end up clogged with debris. In most cases, the debris is usually a bunch of leaves wedged in the vent stack or nesting material packed by birds, rodents or other small animals. When this happens, you may experience the following problems:

  • Your toilet drains sluggishly, but there's no clog or blockages in the drain line itself
  • You start smelling odd odors from your toilet
  • You hear gurgling or bubbling from your toilet
  • When you flush your toilet, the bowl portion refills slowly or fails to refill at all
  • The overall flushing action of your toilet appears weak

These problems can also occur if the vent happens to be missing. It's also not uncommon for builders and plumbers to omit vent lines during construction due to cost overruns or schedule constraints. Without a vent line to help equalize pressures, sewer gases could make their way through the sink and shower faucets instead.

How to Solve the Problem

If you suspect there's a blockage in the vent pipe, it's possible for you to clear the blockage on your own. However, you'll need a ladder and access to your roof in order to carry out this task:

  • Locate the vent line on your roof and use a sturdy ladder to access it. You'll also need to bring with you a garden hose with an adjustable nozzle and a long plumbing snake.
  • Disconnect the vent cap, if your vent line already has one, and carefully inspect the vent for any signs of obstruction. Remove any debris you see around the vent by hand.
  • Feed the plumbing snake into the vent opening until you encounter the blockage. Work the snake head until the blockage is broken through, and then retract the plumbing snake. In most cases, the blockage will be pulled out of the vent along with the snake.
  • Using your adjustable nozzle's jet setting, aim directly into the vent opening and blast any remaining debris into the main waste line.

If you're not comfortable with performing this task on your own, don't hesitate to have a trained professional handle it for you. If the vent line is missing, broken or disconnected within the building, then you'll have to have a plumber cut through the walls to examine and repair the damage. For more information about plumbing services in your area, you can visit http://plumbingandair.com