Assess the specific situation Find the affected drain and extent of backup Check if multiple drains are influenced (indicates most important line challenge) Try to find obvious water destruction or overflow Standard Do it yourself Measures Pour boiling h2o down drain Use plunger suitable for sink/toilet Check out baking soda https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/