A sewage smell inside the house is your plumbing system trying to tell you something is wrong.
What's Usually Going On
Most sewage smell in house calls trace back to a handful of common causes: aging parts, mineral buildup, a loose connection, or normal wear that finally caught up with a fixture. A quick inspection almost always tells us which one it is.
What You Can Check First
If it's safe to do so, check the shutoff valve nearest the fixture, look for visible pooling or staining, and note whether the issue affects one fixture or the whole house — that alone narrows down the cause considerably.
When to Call a Plumber
If the problem is spreading, getting worse, or you're not confident diagnosing it safely, it's time to call. Waiting on a plumbing issue almost always costs more than handling it early.