It is required by plumbing code and is often part of installing a new sink since an old trap assembly doesn't always fit the new sink configuration. When parts of a trap corrode or the joints begin to leak and can't be fixed by tightening the connecting nuts, it's time to replace the entire trap assembly.

How often should you change P trap?

As a preventative measure, many plumbing experts suggest cleaning your drain and plumbing traps at least four times per year. Families with homes of six or more are strongly encouraged to clean their plumbing traps monthly to avoid clogging and limit residue buildup.

How do I know if my P trap is bad?

Bad smells – If your vent line is clogged, water may not flow properly through your drain system. As a result, the p-traps under your sinks or toilets may become dry and sewer gas may accumulate, causing a foul odor throughout your home.