Sink Smells Like Rotten Eggs: Drain, Overflow or Plumbing?
Identify whether odor comes from drain opening, overflow channel or under-sink plumbing; persistent sewer odor needs plumbing diagnosis.
Identify whether odor comes from drain opening, overflow channel or under-sink plumbing; persistent sewer odor needs plumbing diagnosis.
What to do now
- Smell-check drain and overflow separately.
- Run water in rarely used sinks.
- Clean accessible stopper/overflow debris safely.
- Check under sink for leaks.
- Escalate persistent sewer odor or gurgling.
Decision table
| What you notice | Most useful interpretation | Next action |
|---|---|---|
| Problem improves after the first corrective step | The suspected source was probably relevant | Keep the corrected routine and recheck after normal use. |
| Problem returns quickly | A source remains or the first diagnosis was incomplete | Narrow the location/timing and inspect the next likely source. |
| Visible leak, damage or persistent sewer/burning odor | This is no longer a routine cleaning problem | Stop repeated cleaning and move to repair or professional diagnosis. |
Common mistakes
- Masking the problem before identifying the source.
- Using more product than the label directs.
- Skipping drying, airflow or maintenance after cleaning.