Core TradesQuestion 86 of 700
An air admittance valve (AAV) is installed to vent an island sink where a conventional vent is impractical. The AAV must be installed:
a.Below the trap weir, sealed airtight
b.Horizontally under the floor
c.Above the trap arm, in an accessible and ventilated location, at the required height
d.Outdoors at the roofline
Explanation
An AAV is a one-way valve that admits air to break siphon action; it must be located above the horizontal trap arm (per manufacturer height), remain accessible for service, and be in a ventilated space. Placing it below the trap weir, buried, or outdoors defeats its function or accessibility.
Law Reference: 2025 CA Plumbing CodePractice all 700 questions free — no signup required.
Related questions on this topic
- CALCULATION: A branch circuit is protected by a 20-ampere breaker. Applying the common rule that a continuous load should not exceed 80 percent of the breaker rating, what is the maximum continuous load in amperes?
- When routing a nonmetallic-sheathed cable through holes bored in wood studs, the code generally requires that the hole be kept back from the stud edge, or a steel plate be installed, primarily to:
- A fixture drain is located far from any vent, and after installation the trap seals siphon out, letting sewer gas into the room. The MOST likely code violation is:
- CALCULATION: A 3-inch horizontal drain pipe is installed at the common 1/4 inch per foot slope. Over a 40-foot run, how much does the invert drop from start to end?
- A wet vent serves a bathroom group. The key characteristic of a wet vent is that:
- A garden hose is left submerged in a utility sink filled with soapy water while the faucet is on. This creates a cross-connection hazard because:
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against California CSLB General Building (B) Trade Examination · How we review