Evaluate the problem Track down the impacted drain and extent of backup Verify if multiple drains are influenced (indicates most important line situation) Try to find obvious water destruction or overflow Standard DIY Methods Pour boiling water down drain Use plunger appropriate for sink/rest room Attempt baking soda + vinegar https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/