Assess the specific situation Find the affected drain and extent of backup Test if many drains are impacted (implies key line situation) Try to find visible drinking water injury or overflow Basic Do-it-yourself Actions Pour boiling h2o down drain Use plunger appropriate for sink/bathroom Try baking soda + vinegar Option https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/