Evaluate the specific situation Locate the afflicted drain and extent of backup Check out if several drains are afflicted (signifies main line challenge) Try to find obvious water problems or overflow Simple Do it yourself Measures Pour boiling h2o down drain Use plunger appropriate for sink/bathroom Check out baking soda https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/