How to Repair a Leaky Single-Handle Cartridge Faucet

Single-handle cartridge faucet with leaking water being repaired

The Spruce / Kevin Norris

Project Overview
  • Working Time: 42 mins
  • Total Time: 45 mins
  • Skill Level: Beginner
  • Estimated Cost: $10 to $25

The cartridge faucet is a special type of washerless fixture commonly used in kitchens and bathrooms. It's designed so that the cartridge insert is easy to replace when the faucet begins to drip and leak.

Cartridge faucets come in both single-lever and two-handle versions, and various models use different types of plastic or brass-body cartridges. In a single-handle faucet, the handle raises or lowers the cartridge within the faucet body to start and stop the flow of water. Both hot and cold water flow into the same cartridge, and a turn of the handle controls the mixture and temperature. Two-handle cartridge faucets operate similarly, but in this design, there are two cartridges, each controlling the flow of either hot or cold water. In these, the motion of the handle twists the cartridge rather than lifting it up and down. 

The type of water control valve your faucet uses is not always readily apparent just by looking at the faucet. For example, a single-handle kitchen faucet could use a ball, a disc, or a cartridge faucet valve. Usually, though, a single-handle cartridge faucet will give you the distinct sensation of the inner cartridge lifting upward when you turn the water on. With ball-type or disc-type faucets, the sensation is inner parts sliding or rotating. 

This project discusses only the cartridge-type single-handle faucet. Some faucet models are more complex than others but these instructions will apply to most situations.

Before You Begin

The first step in the faucet repair is to locate the water shutoffs and turn off both hot and cold water supply lines running to the faucet. The water shutoff is usually found directly under the sink and consists of a small valve and a small handle—one for the cold water pipe and one for the hot water.

In most cases, you will turn the handle clockwise to tighten it and shut it off. Make sure the valves are turned snugly tight. Other types of valves may have a lever handle that is closed by turning them perpendicular to the water line.

If your house does not have local shutoff valves, then you'll need to go to the water main and shut off the water supply there.

Once the water is shut off, open the faucet to fully release any pressure and let the water drain out.

What You'll Need

Equipment / Tools

  • Allen (hex) wrench
  • Pipe wrench or channel-lock pliers
  • Screwdriver
  • Utility knife


  • Replacement cartridge valve
  • Old toothbrush
  • Heatproof silicone plumber's grease


Materials and tools to repair a leaky single-handle cartridge faucet

The Spruce / Kevin Norris

  1. Remove the Faucet Lever Handle

    To remove the old cartridge, you first have to remove the handle. This can be a bit tricky since manufacturers often conceal the screw that holds the handle under a removable plastic cover plate or cap. This cap may be found on the top of the handle, on the sides, or it may be an exposed Allen-head set-screw on the side of the faucet handle body.

    Put sink basket strainers in the drain to help catch any falling parts before you begin taking the faucet apart.

    Access the handle screw by carefully prying the plastic cap up with a thin-blade screwdriver. If your faucet does not have a plastic cap, the screw might be concealed under a decorative sticker on top of the faucet cap, as is the case on some older Moen-brand faucets. Carefully lift the sticker with a knife blade and remove the sticker.

    Once the handle screw is exposed, use a Phillips-head screwdriver or Allen wrench to remove the screw, then lift and remove the handle. In some cases, this is a simple matter of loosening the set-screw to remove the handle. You may have to gently pry the handle off.

    Set the handle and screw aside.

    Lever handle removed from faucet with Allen-head screwdriver

    The Spruce / Kevin Norris


    As you work, it's a good idea to line up the parts on your counter in the order they were removed. This will make reassembly a little easier.

  2. Remove the Retaining Nut

    The way in which the cartridge is held in place will vary, depending on the faucet model you have. In most cases, there will be some kind of retaining nut that secures it in place within the faucet body. Older, simpler faucets retain the cartridge with just a large nut that is exposed once the handle is removed. Newer or more expensive cartridge faucets may have a decorative collar and other parts that need to be removed before you can reach the retaining nut.

    If you see the retaining nut once the handle is removed, use channel-type pliers or an adjustable wrench to turn the retaining nut counter-clockwise and remove it. Set the nut aside.

    Retaining nut removed from faucet body with wrench

    The Spruce / Kevin Norris

  3. Variation: When the Retaining Nut Is Not Visible

    ​If you do not readily see a retaining nut once the handle is removed, you have a newer, more complicated cartridge faucet. Set all following parts aside in the order they were removed. 

    First, unscrew the decorative collar. Once removed, you may find a bracket attached to the cartridge by a Phillips-head screw that was controlled by the handle. Unscrew the screw to remove the bracket for the handle adapter/connector.

    Once that bracket is removed you may find a white plastic ring that sits inside the faucet body. Remove the ring and be sure to note the orientation of the plastic pivot-stop ring in any keyway in the faucet body. This ring will orient the movement of the handle.

    Remove the stem washer. With these parts removed, you should now see the retainer nut that holds the cartridge in place. Remove the retainer nut.

    Insert a flat-blade screwdriver behind the clip and gently pry it away from its retention slot. You can also try this with needle-nose pliers.​ Carefully remove the clip, then set it aside with other parts in the order it was removed.

    Decorative collar removed from faucet cartridge

    The Spruce / Kevin Norris

  4. Remove the Retention Clip (If Present) and the Old Cartridge

    Some faucets will have a cartridge retention clip: This is a U-shaped brass clip that holds the cartridge in place within the faucet body and (if present) must be removed before the cartridge can be removed. The clip surrounds two plastic tabs on the cartridge body. (You will need to copy this precise orientation when the cartridge is replaced.) To remove the cartridge clip, insert a flat-blade screwdriver behind the clip and gently pry it away from its retention slot. You can also try this with needle-nose pliers.​ Carefully remove the clip, then set it aside with other parts in the order it was removed.

    With the cartridge free of all clips and fasteners (if they were present), it can be removed by lifting it up and out. This can be harder than it sounds because minerals in the water can make your cartridge stick. That’s why your new cartridge kit usually comes with a white plastic tool with a square top to help you loosen the cartridge.

    Place the tool on top of the cartridge stem and line up the notches in the plastic tool with the tabs on the cartridge. You want it to fit squarely on top of the cartridge.

    Using an adjustable wrench or pliers, grab the square top of the plastic tool and twist the cartridge back and forth in its housing to loosen it.

    Remove the plastic tool and use the pliers to firmly grasp the top of the cartridge stem and pull straight up to lift the cartridge out of the faucet body. Some water will come out with the cartridge—that’s normal.

    If the cartridge is stuck and you cannot remove it, you will have to use a cartridge puller.

    Cartridge retention clip removed from within faucet body

    The Spruce / Kevin Norris

  5. Purchase the New Cartridge

    Purchase a new replacement cartridge. There are many dozens of replacement cartridges sold, so make sure you are buying the correct one. Taking the old cartridge with you to the store for comparison is often the best way to avoid mistakes.

    Replacement cartridge held in front of faucet

    The Spruce / Kevin Norris

  6. Install the New Cartridge

    The new cartridge is simple to replace—just take care to align it properly as it goes in.

    Using heatproof silicone plumber's grease, apply a light coating to all rubber O-rings and rubber seals on the cartridge. Then, pull the top of the stem to the UP position to open the cartridge.

    Gently place the cartridge back into the faucet body and push down until it is fully seated, making sure the two cartridge tabs are precisely aligned with the retaining clip notch or slots in the faucet’s cartridge housing. You may need to use pliers to grab the top of the cartridge stem and push the cartridge down fully.

    Install the retainer clip by placing it back into its slot until fully seated. You may need to twist the cartridge a bit to get the clip fully seated if the cartridge tabs were not precisely aligned with the retaining clip notches. If you use the white plastic tool to slightly twist the cartridge while pushing the clip into position, it should click into place.

    Heatproof silicone plumber's grease lightly coating O-ring

    The Spruce / Kevin Norris

  7. Reassemble the Faucet

    Once the cartridge is in place, the faucet is reassembled in the reverse order of disassembly.

    Replace the retaining nut and other parts as appropriate to the model faucet. Turn the water valves back on and test for leaks.


    If you assemble the faucet and find that the hot and cold water controls are reversed, then you have installed the cartridge backward. Disassemble and remove the cartridge, and rotate it 180 degrees before reinstalling. 

    New cartridge inserted into faucet body

    The Spruce / Kevin Norris

Watch Now: How to Repair a Two-Handle Cartridge Faucet

Article Sources
The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Hard Water Issues. North Dakota State University.