Residential plumbing codes stipulate the number of vents needed in your home, the size of your home’s vent pipes and other specs that will ensure fully adequate venting in your living space. As time passes, however, obstructions inside vents or other forms of deterioration may degrade normal venting function.
How Vents Work
Waste water passing through a drain line can displace air inside a pipe, pushing a column of air ahead of the water to create positive pressure. A zone of negative pressure (suction) forms behind the flow. Vent pipes, also known as “stacks,” are dry vertical pipes that extend from the drain lines to the roof to equalize that pressure difference.
What Happens When They Don’t?
The symptoms of poorly vented drain lines can be varied and mystifying to most homeowner. Because they may mimic other plumbing malfunctions, DIY attempts to solve these problems usually miss the mark. If the answer is “yes” to any of the following questions, ask a professional plumber to check your drain and vent system:
- Does the water level in your toilet bowl drop unusually low, then spontaneously return to normal later? Or, maybe you’re seeing mysterious bubbles in your bowl—particularly when an appliance like a washing machine is discharging drain water. These symptoms may indicate pressure imbalances caused by blocked vents.
- Are you tired of plunging a slow drain with no improvement? Maybe the clog is in the air vent, not the drain pipe itself. When positive and negative pressures inside the drain pipe can’t equalize, drain action is often inhibited.
- Are you hearing burps and gurgling noises from your drain? If a vent is blocked, water entering the drain system elsewhere in your home may be pushing air up out of other drains.
- Do you smell a strange odor? If pungent odors are detectable, poorly vented drain lines may be the cause. The suction that forms inside drain pipes can siphon water out of the P-traps under your sink. A dry trap allows noxious sewer gas to flow out of the drain line and infiltrate your living space.
For professional help resolving poorly vented drain lines, contact Team Bob’s Heating Cooling Plumbing in Traverse City today.
Our goal is to help educate our customers in Traverse City, Michigan and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about drain lines and other HVAC topics, download our free Home Comfort Resource guide.
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