Most bathroom faucets that have two handles are cartridge-style faucets. Each faucet handle (hot and cold) has its own cartridge, a valve that turns with the handle to control the flow of water into the faucet spout. If you have a very old two-handle faucet, it may be a compression-type rather than a cartridge. You’ll know when you remove the faucet handle, as cartridges are usually plastic and held in place with a metal retaining nut, while compression faucets usually have a metal valve with a flat rubber washer on the bottom.
If your two-handle faucet is leaking, feel the water to determine whether the cold or the hot side is leaking. You need to replace the cartridge on only the side that’s leaking. However, it’s possible that both sides are leaking and you’ll have to replace both cartridges.
Before You Begin
Look under the sink to locate the shutoff valves on the water supply lines for the faucet. Most shutoff valves have a small, football-shaped handle or a lever that rotates. Close the valve for the faucet tap you will be working on by turning the handle clockwise until it stops. If your shutoff valves have levers instead of knobs, rotate the levers until they are perpendicular to the water pipes or tubing (the direction of the water flow).
If your house does not have shutoff valves under the sink, turn off the water supply to the house at the main shutoff valve. Once the water is shut off, open the faucet fully to release any pressure in the water lines and let any water drain out.
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