New or healthy drains that are not experiencing problems need no preventative service. Lines with a history of backups caused by roots, grease, or low spots in a line, on the other hand, may benefit from having preventative maintenance cleanings to avoid emergency service calls. This can save money and time, and prevent clean-ups. The cost or frequency of such a service will vary with each situation. If you notice signs that your drains are slow or may be clogged, such as being unable to flush, backups, odd odors, and noises coming from your lines, it’s probably time to get your sewer or drains cleaned.