Overflow drain at the top of a sink - Ari Triyanto/Shutterstock If you are not a plumber or sink installation expert, there may be some components of your bathroom sink you have yet to learn about.

As its name suggests, a sink’s overflow hole gives water a place to go in the event that the drain is closed or blocked, and the faucet is left on. While the sink’s drain is located at the bottom of ...