A closet bend is the long-sweep 90-degree drain elbow under a toilet. It turns waste from straight down to sideways and carries it into the drain line. It is often a 4-inch by 3-inch reducing size. It sits below the closet flange and wax ring, out of sight.
A closet bend is the curved drain fitting that sits under a toilet. The word "closet" comes from "water closet," an old name for a toilet. The bend turns the toilet's waste flow from straight down to sideways. It then carries that flow into the home's drain line.
What a closet bend does
A toilet drops waste straight down through a hole in the floor. The drain pipe under the floor usually runs sideways. Something has to make that 90-degree turn. That job belongs to the closet bend. It is a long-sweep 90-degree elbow, a gentle change of direction that keeps the curve stretched out. A gentle curve lets waste and water flow through without clogging.
Many closet bends are a 4 inch by 3 inch reducing size. One supplier says this fitting handles "the transition from a 4-inch waste stack to a 3-inch toilet flange." The wide end meets the drain, and the narrower end meets the toilet connection above.
How it fits with the flange and wax ring
The closet bend is one of three parts that join a toilet to the drain. They are easy to mix up.
- The closet flange is the ring that bolts to the floor and holds the toilet down. It sits on top of the bend.
- The wax ring is the soft seal between the toilet and the flange.
- The closet bend is the elbow below both of them, out of sight under the floor.
If a toilet leaks or rocks, the flange or wax ring is the usual cause, not the bend. For help there, see how to fix a broken toilet flange.