Plumbing glossary

Angle Stop

An angle stop (also called an angle valve, fixture shutoff, or supply stop) is a small valve installed at the wall or floor where the supply line connects to an individual fixture — toilet, sink, dishwasher, ice maker, or washing machine. Closing it shuts off water to just that fixture, so you can repair or replace it without cutting off water to the entire house.

Why they're called "angle" stops

The valve body makes a 90-degree turn, changing the direction of flow from the wall (or floor) stub-out to the vertical supply line running up to the faucet or toilet. A straight stop is the same valve but without the 90-degree turn, used when the supply line runs parallel to the wall.

Types

Compression angle stop: the traditional type, connects to copper pipe with a ferrule and compression nut — reliable but requires a bit more skill to install leak-free.
Push-fit angle stop: connects with a push-fit fitting (like SharkBite) — tool-free installation, popular for DIY repairs.
Sweat (soldered) angle stop: soldered directly onto copper pipe — the most permanent, least common in new construction today.

Common failure modes

Angle stops are frequently overlooked until a leak or repair forces attention. The most common issues:

Won't close fully: old compression-style angle stops can wear out and fail to fully seat — common in homes 20+ years old
Stem leaks: dripping around the handle stem, typically cured by tightening the packing nut
Corrosion: zinc-alloy (pot metal) bodies corrode over time; brass bodies last far longer

Replacement cost

Angle stops cost $5–$20 each. A plumber charges $75–$200 to replace one, including the supply line. Proactive replacement of all angle stops when remodeling a kitchen or bathroom is cheap insurance — typically $150–$400 for the whole set.

Tip

Know where every angle stop is in your home before you need it. Under every sink, behind every toilet, behind the washing machine, and at the refrigerator ice maker. A burst supply line with a seized angle stop becomes a whole-house shutoff situation fast.