Evaluate the Situation Find the impacted drain and extent of backup Look at if multiple drains are afflicted (suggests main line problem) Try to find noticeable water harm or overflow Fundamental DIY Ways Pour boiling drinking water down drain Use plunger appropriate for sink/rest room Consider baking soda + vinegar https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/