Oatey Sure-Vent 1-1/2 in.–2 in. 160 Branch, 24 Stack DFU A

The Verdict

The Oatey Sure-Vent 160 Branch is the air admittance valve (AAV) you grab when you’re done messing around with undersized vents. This isn’t the little 1/2-inch studor vent you jam under a kitchen sink. At 1-1/2 to 2 inches with a 160 DFU branch rating, this is a workhorse for re-pipes, island sinks, and adding bathrooms where running a vent stack through the roof just isn’t practical.

What you actually get: The valve body, a solvent-weld hub that fits 1-1/2 in. or 2 in. pipe, and the internal diaphragm mechanism. Installation is straightforward — you glue it onto a vertical riser, making sure the arrow points up, and ensure it sits at least 4 inches above the highest horizontal branch entering the stack. As shown in the product image, the check valve is built into a compact ABS/PP body that won’t take up much room in a stud wall.

Performance and build quality: The 160 DFU branch rating is the headline here. For context, a standard bathroom group (toilet, sink, tub) is about 6 DFUs. This valve handles 160 — meaning you can vent multiple bathrooms off one unit, which is why plumbers reach for it on remodels. The stack rating of 24 DFU covers most residential stack venting needs. The diaphragm responds quickly; water draining creates negative pressure, the diaphragm lifts, and air rushes in to equalize — no gurgling, no trap siphonage.

Where it shines: Buyers consistently praise how it kills drain noise and sewer gas smells. One reviewer noted, “I used this on a kitchen island sink where we couldn’t run a vent to the roof. Two years later, zero gurgle, zero smell.” Another mentioned passing inspection on the first try, which matters when your local inspector is particular about AAV placement. The solvent-weld connection gives you a permanent, leak-proof joint — no rubber gaskets that can dry out.

Where it falls short: This valve is not a universal solution. If you have a septic system, most codes won’t allow an AAV as the sole vent — you need a real vent path for methane relief. The 4-inch vertical clearance requirement also catches DIYers off guard; you can’t just tee this into a horizontal run. And the plastic threads on the cap can crack if you over-torque — hand-tighten, don’t wrench it. A few reviewers reported the mechanism sticking after years of hard water buildup, though that’s rare and usually a maintenance issue.

Who should buy this:

• DIY remodelers adding a bathroom or kitchen in a location where roof venting is impossible
• Plumbers needing a code-compliant vent solution for island sinks or wet venting scenarios
• Homeowners with chronic gurgling drains from undersized vents

Skip it if: You’re on septic, your local code requires a roof vent for all fixtures, or you need a vent for a single fixture only — the smaller 1/2-inch version is cheaper and sufficient.

FAQ:

Q: Can I use this outdoors or in an unconditioned attic? A: No. AAVs are rated for indoor use only. Freezing temperatures can damage the diaphragm and cause it to fail permanently.

Q: Does this replace the need for a roof vent entirely? A: In most residential applications, yes — as long as the system has at least one primary vent to the outdoors and you follow local code. It’s a supplementary vent, not a substitute for the main stack vent.

Q: Will this fit my 2-inch ABS drain line? A: Yes, the hub is sized for both 1-1/2 in. and 2 in. pipe. Use the appropriate solvent cement for your pipe material — ABS cement for ABS pipe, PVC cement for PVC.

The Verdict: 4.6/5

Buy it if you need a reliable, high-capacity air admittance valve that passes inspection and handles multiple fixtures without drama.

Skip it if you’re on septic, need a quick single-fixture fix (get the smaller Sure-Vent), or your inspector demands a traditional roof vent.

For the price, this is the AAV I’d spec on any remodel where a vent stack isn’t feasible. It’s not glamorous, but it solves a real problem — and 229 buyers at 4.6 stars agree.

Where to Buy

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Last updated: 2026-08-06. Ratings and prices current as of review date. Verify on Amazon before purchasing.