Start with observations
Warning signs your drains need attention
The pattern can be more informative than the worst-looking fixture. Note whether slow drainage affects one sink, several bathroom fixtures or different rooms. Tell us if running water in one place seems to affect another drain, or if the same clog has returned after previous work.
Gurgling, unpleasant odors, water around a floor drain and water returning into a fixture are also worth reporting. These signs do not all have the same cause. Include them in the request so the plumber can consider the drainage system rather than only the first symptom.
