Assess the specific situation Identify the impacted drain and extent of backup Check if many drains are affected (suggests main line situation) Look for noticeable h2o harm or overflow Standard Do it yourself Measures Pour boiling drinking water down drain Use plunger suitable for sink/toilet Try out baking soda + https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/