Quick Answer:
If you hear gurgling right after installing a vent device, it often means the vent is not letting air flow as intended — either it’s closed, installed incorrectly, or the whole venting system is undersized for the fixture. First check the device rating and whether it can move freely. You can also test airflow by opening a nearby window or vent if it’s safe to do so. If the noise continues or multiple fixtures are affected, get a plumber involved.
Why This Happens
- The vent device (air admittance valve or mechanical vent) may be stuck closed or installed backwards, so it does not admit air when the drain needs it.
- The device might not be rated for the quantity of airflow your fixture creates. A wrong rating or wrong type for that stack can let vacuum build up and siphon traps.
- Partial blockages in the drain can change flow and cause gurgling as air tries to move past restricted areas.
- Sometimes the gurgling is a symptom of wider pressure changes in the house. If you notice bubbling with flushing, see **Toilet bubbles after pressure change** for related causes.
Step-by-Step What to Do
Stop and observe
Note when the gurgling happens (only on flush, during shower, after other fixtures run). Is it one fixture or several? Does it follow the new device installation immediately?
Check the vent device rating and orientation
Look at the device markings or packaging. Confirm it’s rated for the type of fixture and vent location where you installed it. Verify it wasn’t installed upside down or with the inlet blocked.
Confirm the device isn’t stuck closed
Gently tap or listen at the device while someone runs water. Many valve-style vents will make a small sound or move when they open. Do not force the device apart — that can damage it. If it seems seized or jammed, it should be replaced.
Test airflow by opening a window or nearby vent (if safe)
Open a window near the fixture or a nearby passive vent to provide alternative air. If the gurgling stops or changes, that indicates the problem is venting/airflow rather than a full blockage. Only do this if it’s safe — don’t climb onto the roof or remove roof vents yourself.
Check for slow drainage or multiple affected fixtures
- Run water in sinks, tubs, and flush toilets. If drains are slow or several fixtures gurgle, that points to a deeper drain or vent sizing problem rather than just the device.
- A single isolated fixture is more likely a local vent or trap issue.
Replace with a correctly rated device if needed
If the device is wrong for the application or it’s clearly stuck, replace it with one rated for that fixture and installation location. Keep the manufacturer’s instructions handy and follow them for orientation and clearance.
What Not to Do
- Do not assume the vent device alone will solve gurgling — correct vent sizing and placement matter. Don’t rely solely on the gadget as a fix.
- Don’t tear apart roof vents, climb on the roof, or remove plumbing parts beyond basic inspection unless you’re trained and safe equipment is used.
- Don’t ignore persistent gurgling or signs of sewer smell. That can indicate more serious venting or blockage issues.
- Don’t use aggressive chemicals to “fix” a venting problem — they won’t correct improper vent sizing and can damage pipes or seals.
- If you’re unsure about diagnosis or correct sizing, a plumber is appropriate — don’t guess at major changes.
When to Call a Professional
- If gurgling continues after replacing or reseating the device, call a plumber.
- When multiple fixtures gurgle or drains are slow, that often means a vent or main drain problem that needs professional assessment.
- If you notice sewage smell, backups, or the issue affects an upper-floor bathroom such as **Toilet gurgles upstairs only**, call a plumber promptly to avoid contamination and larger repairs.
Safety Notes
- Do not climb on roofs or ladders unless you have proper training and safety gear.
- Do not disassemble sealed plumbing devices or cut pipes without turning off water and knowing how to restore the system safely.
- Avoid chemical drain cleaners for venting problems; they are unsafe for many pipe materials and won’t fix air-flow issues.
- If you smell gas or strong sewage odors, ventilate the area, leave the house, and call a professional immediately.
Common Homeowner Questions
- Why did the gurgling start only after I installed the new device? — The new device may be stuck, improperly oriented, or not rated for that venting demand, so the system’s air balance changed.
- Can I swap the device myself? — You can replace a clearly defective valve with the same rated model, but don’t modify venting or change pipe sizing without professional guidance.
- How long should I wait before calling a plumber? — If the noise persists after basic checks and a simple replacement, or if more than one fixture is affected, call a plumber the same day or next business day.