What a faucet cartridge is and why it fails

A faucet cartridge is the valve mechanism inside your faucet that controls water flow and temperature. It looks like a small cylinder or spool, usually made of plastic or brass, and it moves back and forth or twists to mix hot and cold water. When a cartridge wears out, you get a dripping faucet, water that won't shut off completely, or a handle that feels stuck or loose.

Cartridges fail because the seals inside them degrade over time. Hard water deposits, sediment, and normal wear all speed this up. The good news: replacing one takes about 30 minutes, costs $15 to $50 for the cartridge itself, and requires only basic tools you likely already own.

The hardest part is identifying which cartridge your faucet uses. Faucet makers use different designs, and putting the wrong cartridge in will not work. You will need your faucet's brand name and model number before you buy a replacement.

Key Takeaways

  • Find your faucet's brand and model number on the faucet body or in your home's paperwork, then search online or call the maker to confirm which cartridge you need.
  • Turn off the water supply under the sink before you start, and open the faucet to release any pressure in the lines.
  • Remove the handle by prying off a decorative cap, unscrewing a set screw, or both, depending on your faucet design.
  • Use a cartridge puller tool (rented or bought for $10 to $30) to remove the old cartridge, because pulling by hand usually fails and can damage the faucet body.
  • Install the new cartridge in the same orientation as the old one, reassemble the handle, and test for leaks before you turn the water back on fully.

Finding the right cartridge for your faucet

Before you buy anything, you need to know what you are replacing. Look at the faucet body itself—most brands stamp or print the model number somewhere visible. Common locations are the underside of the spout, the back of the faucet body, or on a label stuck to the base. Write down the brand name and the full model number.

If you cannot find a number on the faucet, check your home's paperwork. The faucet receipt, warranty card, or home inspection report often lists the model. If you have neither, take a photo of the faucet and call the manufacturer's customer service line. Tell them the brand and describe the faucet (single handle, double handle, color, finish). They will tell you the model and which cartridge fits.

Once you have the model number, search online for "[brand] [model] cartridge replacement" or visit the maker's website. Most brands sell cartridges directly or list authorized retailers. Buy the cartridge before you start the job—you do not want to have the water off and the faucet apart while you wait for a delivery.

Turning off the water and preparing the workspace

Locate the shut-off valves under the sink. There are usually two: one for hot water and one for cold. Turn both clockwise until they stop. If you cannot find them or they do not turn, locate your home's main water shut-off valve (usually in the basement, crawlspace, or outside) and turn that off instead.

Open the faucet handle all the way to release any water pressure trapped in the lines. You should hear air hiss out. Leave the handle open while you work.

Place a towel or bucket under the sink to catch any water that drips from the lines. Have a second towel nearby to dry your hands and the work area as you go. Good lighting is essential—use a headlamp or position a work light so you can see inside the faucet body clearly.

Removing the faucet handle

The handle is held on by one of three methods: a decorative cap that pries off, a set screw that unscrews, or both. Look closely at the base of the handle where it meets the faucet body.

If you see a small cap (often chrome, plastic, or colored to match the handle), use a flat-head screwdriver or a plastic pry tool to gently pop it off. Do not use a metal screwdriver directly on a polished finish—wrap the tip in a cloth first to avoid scratching. Once the cap is off, you will see a screw underneath. Unscrew it counterclockwise and set it aside in a small container so you do not lose it.

If there is no cap, look for a screw on the side of the handle or at the base. Unscrew it the same way. Once the screw is out, pull the handle straight up and away from the faucet body. It may take a little wiggling, but it should come free without force.

Removing the old cartridge with a puller tool

Now you can see the cartridge. It is the cylindrical part sticking up from the faucet body, usually with a flat top or a small notch. Do not try to pull it out by hand—cartridges are wedged in tight, and you will likely twist or crack the faucet body if you force it.

Rent or buy a cartridge puller from a hardware store or online. The tool costs $10 to $30 to buy, or $3 to $5 to rent for a day. It looks like a small claw or socket that threads onto the top of the cartridge. Follow the tool's instructions: usually you thread it onto the cartridge, tighten it hand-tight, then turn a center screw or handle to pull the cartridge straight up and out of the faucet body.

Once the cartridge is out, inspect the faucet body for any debris or mineral buildup. If you see white or tan crusty deposits, soak a cloth in white vinegar and wipe the inside of the cavity where the cartridge sat. Let it dry completely before you install the new one.

Installing the new cartridge and reassembling

Before you insert the new cartridge, check its orientation. Most cartridges have a flat side, a notch, or a small arrow that shows which way it should face. Look at where the old cartridge came from and match that orientation exactly. If you install it backwards, the hot and cold will be reversed, or the handle will not move the way it should.

Slide the new cartridge straight down into the faucet body. It should fit snugly but not require force. If it does not slide in smoothly, stop and double-check the orientation. Once it is fully seated, you should not see any of the cartridge sticking above the faucet body.

Slide the handle back onto the cartridge stem, align the screw hole, and insert the screw. Tighten it by hand first, then use a screwdriver to snug it down—firm but not so tight that you crack the handle. Pop the decorative cap back on if your faucet has one. It should click or snap into place.

Testing for leaks and turning the water back on

Before you fully restore water pressure, do a slow test. Turn the shut-off valves under the sink counterclockwise about one full turn. Open the faucet handle and let water run for 10 to 15 seconds. Check underneath the sink for any drips from the faucet body or the connection points. If you see water, turn the shut-off valves back off and tighten the connection nuts under the sink with a wrench.

Once you confirm there are no leaks, turn the shut-off valves all the way open. Test the faucet handle in all positions—hot, cold, and mixed. The water should flow smoothly, the handle should move without sticking, and there should be no drips from the spout when the handle is fully off.

If the faucet still drips or the handle feels wrong, the cartridge may be installed backwards or the wrong model. Turn the water off, remove the handle, and check the cartridge orientation against your faucet maker's diagram. If you installed it correctly and it still does not work, the cartridge itself may be defective—contact the retailer for a replacement.

When to call a plumber instead

If the shut-off valves under the sink do not turn or are leaking, stop and call a plumber. Forcing a stuck valve can break it, and you will need professional help to replace it. Similarly, if the faucet body itself is cracked or if water sprays from inside the faucet when you remove the handle, the faucet may need replacement rather than just a cartridge swap.

If you have removed the handle and cannot see a clear cartridge, or if the cartridge is so stuck that a puller tool cannot budge it, a plumber has specialized tools and experience to extract it without damaging the faucet. This is rare, but it happens with very old faucets or ones that have mineral buildup.

Frequently Asked Questions

How do I know if my faucet has a cartridge or a different type of valve?

Single-handle faucets almost always use a cartridge. Double-handle faucets usually have separate cartridges for hot and cold, or they use ball or disk valves instead. If you remove the handle and see a cylindrical part sticking up from the faucet body, it is a cartridge. If you see a rounded ball or a flat disk, it is a different type—search for "ball valve faucet repair" or "disk valve faucet repair" instead.

Can I replace just the seals inside the cartridge instead of the whole cartridge?

Some cartridges have replaceable seals, but most do not. Cartridge repair kits exist for certain brands, but they are fiddly and often cost nearly as much as a new cartridge. Replacing the whole cartridge is faster and more reliable. If you want to try a repair kit, confirm your faucet model supports one before you buy.

What if hot and cold are reversed after I install the new cartridge?

You installed the cartridge backwards. Turn the water off, remove the handle, and rotate the cartridge 180 degrees. Reinstall it and test again. Some faucet makers mark the cartridge with an arrow or flat edge to show the correct direction—check your cartridge or the maker's instructions.

Do I need to drain the pipes before I turn off the water?

No. Turning off the shut-off valves under the sink stops water from entering the faucet. Opening the faucet handle releases pressure in the lines above the shut-off point. That is all you need. The pipes below the shut-off valves will have some water in them, which is why you place a towel underneath.

How long does a new cartridge usually last?

A new cartridge typically lasts 10 to 15 years, depending on water quality and how often the faucet is used. Hard water and high mineral content shorten the lifespan. If you have very hard water, a whole-house water softener can extend the life of all your faucets and appliances.