Sewer Line Warning Signs
A single slow drain is local. Several at once usually means the shared line.
Call for Plumbing HelpSymptoms that point at the main
Toilets that gurgle when a washing machine drains, a tub that backs up when a toilet is flushed, and several fixtures slowing down together all suggest a restriction downstream of the branch lines.
Outside the house
A patch of yard that stays green or soggy in dry weather, sunken ground along the line's path, or sewage odor near a cleanout are signs the line may be broken rather than just blocked.
How it gets diagnosed
A camera inspection through the cleanout shows whether the line is blocked by roots or grease, offset at a joint, bellied, or collapsed. That distinction decides whether it is a cleaning, a spot repair, or a replacement.