A kitchen faucet that drips is the most common household plumbing problem. Dripping usually occurs when the O-ring inside the faucet's aerator has worn out or broken. Left unchecked, a dripping kitchen faucet can have a significant impact on the water bill and can eventually carve a channel into the metal faucet seat. Thankfully, a dripping kitchen faucet can easily and inexpensively be repaired with common household tools and a new O-ring.
Remove the aerator from the faucet's spout. The aerator is the last portion of the spout that the water flows through before it exits the faucet. Wrap both jaws of a pair of pliers with masking tape to avoid scratching the aerator when it is removed. Grasp the aerator with the pliers and twist the aerator in a counterclockwise direction to remove it from the faucet's spout.
Remove the O-ring from the aerator. The O-ring is a rubber ring located on the spout side of the aerator. Use a flathead screwdriver to pry the O-ring free from the aerator.
Clean any mineral buildup present on the small holes on the aerator. Use a small brush, such as a toothbrush, dipped in vinegar to brush the mineral deposits away gently.
Insert a new O-ring into the aerator by pressing it into place.
Attach the aerator the faucet's spout. Turn the aerator in a clockwise direction until it is finger-tight, then use the pliers with tape wrapped around the jaws to tighten the aerator onto the spout, thereby completing the repair.