The average cartridge faucet will last for some time before it must be replaced. However, when you need a new cartridge installed, you should strongly consider performing the installation on your own. Replacing a cartridge faucet is simpler than you would think, and mostly consists of a short period of simply removing the entire old faucet followed by inserting and reattaching a replacement. With the following instructions, installing your new faucet should cause you no trouble whatsoever, allowing you to get the best use out of your sink again.
Step 1 - Setting Up
Before you do any work on your faucet whatsoever, you must take steps to ensure that you do not accidentally drench the surrounding area. Begin by turning off the water using the shutoff valve under the sink. If there is no shutoff valve present, you can use the main water valve for your home. Finally, finish up by turning on the faucet as if you were going to use it normally. This allows any water that is still in the pipes to drain out. Once you have finished both of these tasks, you can safely begin to work on removing the faucet.
Step 2 - Removing the Handle
With almost any cartridge faucet, the thing securing it in place will be its handle. Luckily, removing the handle on a cartridge faucet is a simple process. To begin, you will need to gain access to the inner workings of the handle. Do this by removing the handle's decorative cap. This should expose one or more screws holding the handle in place. Get out your screwdriver and remove the screw or screws. Once you have done this, you should be able to lift the handle away from the faucet and set it aside.
Step 3 - Removing the Cartridge
Now that the handle is removed, the inner workings of the cartridge faucet should be accessible. Take a moment to look at the exposed section. You should see either a lock ring or a lock nut. If you see the former, use your screwdriver to remove it; if you see the latter, use your pliers.
Once this mechanism, whatever type it might be, has been removed, you are free to remove the cartridge. Do so with your pliers and set it aside.
Step 4 - Replacing the Cartridge
Once you have the cartridge out, take it to your local hardware store and use it as a reference to buy a suitable replacement that is compatible with your sink. Once you have done this, take the new cartridge home. At this point, you can install your new cartridge faucet by simply performing the previous steps in reverse. Insert the cartridge, fasten it in place using the lock ring or lock nut, then screw the faucet handle into place with your screwdriver. Finish up by replacing the decorative cap.
Step 5 - Finishing Up
Re-open your water supply, whether you have closed it from your sink or from the main line. Turn on your sink and make sure that there are no leaks at any point.