This little opening in a bathroom sink bowl does have a name. In fact, it is referred to by a number of different names, including the “emergency drain,” “overflow protection device” and the “overflow drain.” Its purpose is to prevent rising water in a clogged sink from overflowing. Instead of pouring out onto the sinktop and the bathroom floor, the rising water will seep into the overflow drain and be directed back into the sink’s drain pipe.
Cleaning a Clogged Overflow Drain
It is a relatively rare occurrence that an overflow hole will become clogged. However, if a clog should develop within an overflow drain, it shouldn’t require the assistance of a plumbing professional.
A clog in a sink drain or overflow hole will typically be caused by the buildup of soap scum, hair and other debris that can often be cleared up by the homeowner without too much trouble. But unlike the drain at the bottom of a sink bowl, overflow drain clogs usually cannot be addressed with a plunger due to their location.
Therefore, the best approach is to use an auger or “plumbing snake” to clear debris from the overflow drain assembly. Simply insert the auger into the overflow hole and twist, push and pull, moving it around within the assembly to dislodge any debris. Once you are confident the drain is clear, use a funnel to flush it with hot water. You may also want to use the funnel to insert the auger to prevent damage to the perimeter of the overflow drain.
It is wise to regularly clean sink drains and overflow drains so clogs and plumbing problems can be avoided. Use a drain brush to clean around the insides of these drains. Then flush the drains with boiling water or a baking soda and vinegar mixture. This should keep the drains in your bathroom sink healthy. It will also help you avoid potentially serious drain problems that may require expensive plumbing repairs.
Written and published by Thompson Electric, Plumbing, Heating & Cooling.