Here's how to repair a leaky compression faucet: Turn off the water shut-off valves. Locate the valves—check right below the sink basin and near the back wall—and turn them clockwise until fully tightened. If this isn’t an option, you can also shut off the water main. Drain the faucet of any leftover water before starting the repair process.

Turn off the water to the sink and stuff a rag in the drain. Disassemble the handles by looking for a small screw slot and unscrewing the fastener. If there’s no slot, pry the handle off manually. Depending on the style of sink, you’ll need to replace the rubber O-ring inside the valve or replace the entire assembly.

To repair the leak, simply remove the handle, pull out the ceramic cartridge and replace it with a new cartridge.

If your faucet has a brand name inscribed on its body, look for a repair kit brand to match. Otherwise, dismantle the faucet to find out its type. In some cases, only inexpensive O rings and washers are needed. Other times, a main part—a cartridge, stem, or ball, for instance—needs to be replaced.