Evaluate the specific situation Find the impacted drain and extent of backup Check if many drains are afflicted (implies principal line concern) Hunt for seen water injury or overflow Primary Do it yourself Steps Pour boiling h2o down drain Use plunger suitable for sink/bathroom Test baking soda + vinegar solution https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/