What is a cleanout?

A cleanout is an access point in your home's drain system where a capped pipe rises above ground or sits in a basement wall, allowing a plumber to reach into the line and remove obstructions or send equipment down to clear blockages. The cap sits flush with the ground, basement floor, or crawl space, and when unscrewed, it exposes the interior of the drain pipe.

In Ontario homes, cleanouts are typically installed at the base of soil stacks (the main vertical pipe that collects waste from toilets), at changes in direction along the main sewer line, and sometimes in the yard where the line runs from the house toward the municipal connection. Older homes may have cleanouts only at the foundation or in the basement, while newer construction often includes multiple access points to aid maintenance.

When a drain backs up or moves slowly, a plumber will locate the cleanout, remove the cap, and use a plumbing snake, water jetting equipment, or camera to diagnose and clear the blockage. Without a cleanout, clearing a severely clogged main line becomes much more difficult and costly, sometimes requiring excavation. Locating and maintaining your cleanout helps you know where it is before an emergency occurs, and regular cleaning can prevent backups in the first place.