If the water in your bathroom sink is not flowing down the drain properly, you likely have a clog. Hair, soap scum and grime build up inside the plumbing, which can obstruct the pipes and prevent water from flowing freely. Instead of calling a professional plumber to unclog the drain – and spending a lot of money – try unclogging the bathroom sink yourself. Even the novice do-it-yourselfer can successfully unclog a bathroom sink drain with the right products and methods.
Remove the drain assembly or trap from the sink. Some of these will unscrew, and others will require a screwdriver to remove. Check the owner's manual for your sink for specific instructions on removing the drain assembly and/or trap.
Coat the rim of a plunger with a thin layer of petroleum jelly. This will help to ensure a tight seal. Fill the sink with enough water so it will cover the head of the plunger. If there is more water than what covers the plunger, use a cup to remove some.
Position the suction cup of the plunger over the opening of the drain. Push down to form a tight seal.
Hold the plunger upright and vigorously pump it about 20 times. Repeat this two or three times to effectively unclog the drain.
Pour ¾ cup of baking soda down the drain if it is still clogged. Follow this with ½ cup of white vinegar, then quickly plug the drain with rags. Wait 30 minutes, then dump a pot of boiling water down the drain hole to flush away the clog.