Before you begin fixing or replacing a faulty faucet you should organize your work area. Remove anything from the countertop that could get knocked over, clean out the cabinet under the sink so you have room to work, and gather all the tools and materials you’ll need, including a bucket and some rags.
To start, you’ll need to figure out of the leak is from the valve on the hot water or cold-water side. To do so, shut off one of the water supply lines and monitor the sink for a minute. If the leak stops, that’s the side that’s leaking. If not, turn that supply back on and test the other line. If the leak continues for both, you’ll need to replace both sides (or simply replace the whole faucet).
Before you begin, turn off both water supply lines and open both faucet handles to drain any water in the fixture.
Plug the drain before removing any screws to prevent them falling down the drain. You can also lay a towel in the basin to protect it from scratches. (This can also be where you lay your parts as you remove them.) It’s a good idea to take photos each step of the way as you remove parts so you can refer back to them if you forget a step during reassembly.
Depending on what type of faucet you have, you’ll need either a screwdriver or Allen key to remove the handle. Once that’s out of the way you can access the ceramic disk, cartridge, or gasket. With the leaky part removed, it’s time to head into town for a replacement. To reassemble, follow all the removal steps in reverse.
If the flow from the faucet has slowed to a trickle, something might be plugging the aerator filter. If you can’t loosen it with your fingers (“lefty loosey”), grab some pliers to remove the cap holding it in place. If you use pliers, wrap a towel around the cap to protect it from scratches. Soak the aerator in vinegar for an hour or so and then rinse it out. If it looks damaged, buy a replacement aerator of the same size.
If the water isn’t draining from the basin, there could be a clog in the P-trap below the sink. With your work area prepped—and bucket at the ready—use pliers or a plumber’s wrench to loosen the two threaded nuts on either end of the trap that hold it in place. This is also how you can recover any items that fall down the drain, provided the flowing water hasn’t already pushed them past the trap.
Is a dripping tap keeping you up at night, but you don’t have the energy to break out the tools? Tie a piece of string around the spigot and dangle it down into the drain. The water will silently seep down the string into the drain so you can get a good night’s rest before tackling it in the morning.