Several factors can determine how often you should schedule drain line cleaning. The amount of wastewater that goes down your drains will vary if you have seven people in your household compared to two. The condition and age of your drain pipes are other factors. If you don't know when your drain lines were last cleaned by a professional, get it done now before things get out of hand. For most homeowners, having your drains cleaned once a year is sufficient. But if you have a high volume of usage, your drains may require more frequent drain cleaning.