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Repair & Maintenance

What Are Plumbing Vents?

We depend on indoor plumbing, so plumbing problems can disrupt our households. Learn what issues can cause your vent pipes not to work properly and what to do.

what are plumbing vents

Why Your Home Needs Plumbing Vents

Most homeowners will encounter a plumbing issue now and then, but diagnosing the problem involves more than just checking the water pipes. Plumbing vents can also become clogged or damaged, causing stoppages and a host of other issues. Understanding this sensitive part of your plumbing system is important in order to keep drains flowing smoothly in your home.

What is a Plumbing Vent?

The plumbing vent, also known as a vent stack, helps regulate the air pressure in your plumbing system. Just as drain pipes remove water and waste from your home, the plumbing vent pipe – also known as a plumbing air vent – removes gas and odors. It also allows fresh air into the plumbing system to help water flow smoothly through the drain pipes.However, no water runs through the plumbing vent pipe. It is a vertical pipe attached to a drain line and runs through the roof of your home. The vent stack is the pipe leading to the main roof vent. It channels the exhaust gases to the vent and helps maintain proper atmospheric pressure in the waste system.

Why Plumbing Air Vents Are Important

Your home’s plumbing system is designed to efficiently remove water and waste. Its drainage and vent functions are actually two systems that work together.

Drainage pipes carry waste out of your home to either the city sewer or a septic tank. Vent pipes supply fresh air to each plumbing fixture in the house, which helps the system move water through the drainage pipes each time a toilet is flushed or a sink is drained.

Plumbing air vents also prevent sewer gases from entering the home and allow wastewater gas and odor to escape. Plumbing vent pipes are located on roofs, away from windows or air conditioning units, so that the fumes can easily dissipate.

Problems With Plumbing Vent Pipes

When plumbing air vents or vent stacks do not work properly, neither will your home’s plumbing drainage system. If you hear gurgling sounds coming from your drains, see standing water in your sink or bathtub, or notice a slow drain in the bathroom or kitchen, a blocked vent may be the issue.

When a plumbing vent pipe or vent stack is blocked, negative pressure builds up in drainage pipes and water flow is interrupted. Though you may have success clearing a clogged drain yourself, stoppages will continue to occur if a blocked vent is the culprit.

Ongoing stoppages and slow-flowing drains can lead to sediment forming inside the drain pipes. This can further damage your plumbing system and may result in hefty pipe repair or replacement costs down the road.

If you can't clear a slow-flowing drain with a plunger, auger or drain cleaner the vent blockage may be severe. If the plumbing air vent or vent stack becomes completely blocked, a vacuum will form and you will no longer hear gurgling. You will also be able to smell sewer gases in the rooms where the affected fixtures are located. This is a problem that requires immediate attention from a plumbing professional.

American Home Shield warranties cover a variety of plumbing issues, offering peace of mind when it comes to one of your most important investments – your home.


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