What a cartridge does and why yours might need replacing
A cartridge is the part inside your faucet that controls water flow and temperature. When you turn the handle, you are moving the cartridge, not opening a valve directly. Over time, mineral buildup and wear cause cartridges to stick, leak, or stop mixing hot and cold water properly. Replacing it costs $15 to $50 in parts and takes about half an hour—much cheaper than replacing the entire faucet.
Before you start, turn off the water supply under the sink. Look for two shut-off valves (one for hot, one for cold) and turn both clockwise until they stop. Turn on the faucet to release any remaining pressure. If you cannot find shut-off valves under the sink, you may need to shut off water to the whole house—usually a valve near the water meter or where the main line enters.
Key Takeaways
- Turn off both hot and cold water shut-off valves under the sink before you begin, then turn on the faucet to release pressure.
- Remove the handle by prying off the decorative cap, unscrewing the handle screw, and sliding the handle off the faucet body.
- Use a cartridge puller tool (rented or bought for $10 to $25) to remove the old cartridge straight up—forcing it can break the faucet body.
- Install the new cartridge with the notch or flat side aligned to match the faucet body, then reassemble the handle and test both hot and cold water.
- If water still leaks or temperature does not mix correctly after replacement, the cartridge may be installed backward or the new one may be defective.
Identify your faucet brand and get the right cartridge
Cartridges are not universal—a Moen cartridge will not fit a Kohler faucet. Look under the sink or on the faucet body for the brand name. Common kitchen faucet brands are Moen, Kohler, Delta, Pfister, and Grohe. Write down the brand and any model number you find.
Take a photo of the faucet or write down the model number, then search online for "[brand] kitchen faucet cartridge" or call a local plumbing supply store with the information. The staff can tell you the exact cartridge part number. Buy the cartridge before you take the faucet apart—you do not want to have the water shut off longer than necessary. Cartridges cost $15 to $50 depending on the brand.
Remove the handle and decorative trim
Look at the top of the handle for a small decorative cap or plug, usually made of plastic or metal. Use a flat-head screwdriver or a plastic pry tool to gently pop it off. Do not use a metal screwdriver directly on chrome or stainless steel—wrap the tip in a cloth first to avoid scratching.
Underneath the cap is a screw. Unscrew it by turning counterclockwise. Keep the screw in a small cup or bowl so you do not lose it. Slide the handle straight up and off the faucet body. If it is stuck, wiggle it gently side to side while pulling—do not force it or you may crack the handle.
Remove the cartridge with a puller tool
Once the handle is off, you will see the cartridge stem sticking up from the faucet body. The cartridge is held in place by a nut or clip. If there is a brass or plastic nut, unscrew it counterclockwise by hand or with an adjustable wrench. If there is a metal clip, pry it out carefully with a flat-head screwdriver.
Now use a cartridge puller to remove the cartridge itself. This is a specialized tool that grips the cartridge stem and pulls it straight up. You can rent one from a hardware store for $5 to $10 or buy one for $15 to $25. Slide the puller over the stem, tighten the handle or screw on the puller, and pull straight up with steady pressure. Do not yank or twist—the cartridge should come out smoothly. If it is stuck, explore penetrating oil (like WD-40) around the base and wait 15 minutes before trying again.
Install the new cartridge and reassemble
Before you insert the new cartridge, look at the faucet body for a notch, flat side, or alignment mark. The cartridge has a matching notch or flat side on its stem. Line these up so the cartridge slides in straight. Insert the cartridge slowly and push it all the way down until it sits flush with the faucet body. This alignment matters—if the cartridge is installed backward, hot and cold will be reversed or the handle will not move smoothly.
Reinstall the nut or clip that holds the cartridge in place. Tighten the nut by hand first, then use a wrench to snug it—do not over-tighten or you may crack the cartridge. Slide the handle back onto the stem and screw the handle screw back in. Pop the decorative cap back on.
Test the water and check for leaks
Turn on the hot water shut-off valve under the sink by turning counterclockwise. Wait a few seconds for air to leave the line, then turn on the cold water shut-off valve. Turn on the faucet and let water run for 30 seconds to clear any debris from the new cartridge.
Check that hot and cold water mix correctly when you move the handle. If the temperature is backward (handle to the left gives hot water instead of cold), the cartridge is installed backward. Turn off both shut-off valves, remove the handle and nut, pull the cartridge out, rotate it 180 degrees, and reinstall it. Look under the sink for drips around the nut or from the faucet body. A small drip at the nut usually means it needs to be tightened a quarter turn with a wrench. If water drips from inside the faucet body, the cartridge may be defective—remove it and try a new one.
Common mistakes and how to avoid them
The most common mistake is forcing the cartridge out without a puller tool. The cartridge stem can break inside the faucet body, and then you have to replace the entire faucet. Always rent or buy a puller—it costs less than a new faucet and takes two minutes to use.
The second mistake is installing the cartridge backward. Before you push it in, line up the notch on the cartridge stem with the notch on the faucet body. If you are not sure which way is correct, check the instruction sheet that comes with the new cartridge—it will show a diagram.
The third mistake is over-tightening the nut that holds the cartridge. Hand-tight plus a quarter turn with a wrench is enough. Over-tightening can crack the cartridge or the faucet body and cause leaks that are harder to fix than the original problem.
Frequently Asked Questions
Do I need a cartridge puller or can I pull it out by hand?
A puller is strongly recommended. The cartridge is wedged tightly in the faucet body, and pulling by hand or with pliers can snap the stem inside the faucet, requiring a full faucet replacement. A puller costs $15 to $25 to buy or $5 to $10 to rent and takes the guesswork out of removal.
What if I cannot find the shut-off valves under the sink?
Some older homes do not have shut-off valves at each fixture. If you cannot find them, locate the main water shut-off valve for your house—usually near the water meter in the basement, crawlspace, or outside. Turn it clockwise to stop water to the whole house. After you finish the cartridge replacement, turn it back on counterclockwise.
Can I use the old cartridge as a reference to buy the new one?
Yes. Once you remove the old cartridge, take it to a plumbing supply store or show a photo to a store employee. They can match it to the correct replacement. This is faster and more reliable than trying to identify the cartridge by brand name alone, since some brands make multiple cartridge styles.
Why is my water still leaking after I installed the new cartridge?
Check that the nut holding the cartridge is tight—a loose nut is the most common cause of leaks. If tightening does not stop the leak, the cartridge may be installed backward or the new cartridge may be defective. Remove it, check the alignment, and reinstall. If leaking continues, try a replacement cartridge from a different batch.
How long does a cartridge usually last before it needs replacing?
Cartridge life depends on water hardness and how often the faucet is used. In homes with soft water and moderate use, a cartridge can last 10 to 15 years. Hard water and heavy use can shorten that to 5 to 10 years. When a cartridge starts to stick, leak, or fail to mix temperatures, replacement is the only fix.