Evaluate the specific situation Identify the influenced drain and extent of backup Verify if many drains are affected (signifies key line issue) Seek out obvious h2o harm or overflow Standard Do it yourself Steps Pour boiling water down drain Use plunger appropriate for sink/bathroom Test baking soda + vinegar Alternative https://www.kawatan.net/why-you-should-never-use-baking-soda-and-vinegar-to-unclog-a-drain/