Evaluate the specific situation Locate the affected drain and extent of backup Look at if many drains are impacted (implies major line concern) Search for seen water problems or overflow Simple Do it yourself Measures Pour boiling h2o down drain Use plunger appropriate for sink/bathroom Try baking soda + vinegar https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/