Repairing a Single Handle Disk Faucet

Close up of modern kitchen faucet and sink
Sam Edwards / Getty Images

Repair of a Single Handle Disk Faucet

A common home plumbing repair is fixing a leaky faucet. The problem is, due to the different types of faucets you may find in your home, figuring out what type of faucet you have can make getting started on this simple task seem a bit daunting. For example, let’s say you have a single handle faucet. Well, it could be either a ball faucet or cartridge faucet or a disk faucet (also called a disc faucet).

In this tutorial, we will deal with a special type of washerless kitchen faucet called a disc faucet. (See How to Repair a Leaky Single Handle Cartridge Faucet if you have a cartridge faucet). Disc faucets can be found in the kitchen and bathroom. Disc, cartridge and ball faucets may look similar. Like a cartridge or ball faucet, a disc kitchen faucet may have a single handle. But unlike the ball faucet (which has rounded ball-shaped cap right above the base of the faucet and moves in a spherical direction), the single handle disk faucet has a spout lever over a wide cylindrical body and moves in an up and down and side to side motion, similar to a cartridge faucet.

The disc faucet mixes hot, and cold water inside a mixing chamber called a pressure balance cartridge. Two ceramic discs at the bottom of the chamber will raise and lower to control the volume of water flow. Temperature is controlled by a side-to-side rotation of the handle.

The discs are ceramic which provide long life and aren’t the part that normally wears out. What often fails are the little rubber water inlet seals at the bottom of the cartridge, or else they get fouled with mineral deposits from water. This tutorial will describe how to remove a disc cartridge and inspect, clean and replace the rubber seal/disc cartridge assembly.

Needed Tools and Materials

  • Allen Wrench (hex wrench)
  • Pipe Wrench or Groove-Joint Pliers
  • Screwdriver
  • Utility Knife
  • Replacement disc cartridge replacement or rubber seals (if needed)
  • New O-ring for faucet body (if leaking from spout bottom)
  • Old toothbrush
  • Heatproof Silicone Plumber's Grease

Turn Off Water Supply at Sink

Local water supply shutoff valve
  • The first step in the faucet repair is to locate the water shutoff to your faucet 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.
  • If the valve is similar to the style shown here, turn the handle clockwise to tighten and shut it off. Other types of valves may have a lever handle that needs to be turned perpendicular to the water line to be in a closed position.
  • 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 (see How to Shut Off a Water Supply)
  • Once the water is shut off, then open the faucet fully releasing any pressure and letting the water drain out.

Remove Handle Lever

A fastening screw being removed from a level handle
  • The handle will be attached discreetly to the faucet cartridge. The connection may be concealed under a plastic cover plate as found on the top of some handles as shown in the photo. If your faucet does not have a plastic cap, the handle may be attached by an allen-head set screw on the side, front or rear of the handle.
  • Using a Phillips head screwdriver or an allen wrench, remove the fastening screw and remove the handle and decorative cover plate if used on the faucet. You may have to gently pry the handle off.

Remove Ceramic Disc Cartridge

Pliers removing the disc cartridge
Danze 2013
  • With the handle removed the disc cartridge is now exposed and can be removed.
  • Some styles of cartridges have screws that hold it in place. If you have this style, remove the screws which secure the disc cartridge.
  • Once the screws are removed or if your cartridge has no securing screws. Lift the cartridge out of the faucet body.
  • You may need to use some pliers since these can get stuck a little. If the cartridge is stuck, gently grab it with the groove joint pliers and pull it out.
  • Now that you have the cartridge removed, you must check it for damage. In the unlikely chance, it is cracked, it will need to be replaced. If you have to replace the cartridge, it’s usually a good idea to bring the old one along as it makes finding a replacement a lot more foolproof.
  • If a replacement cartridge is not readily available, you must order one.

Clean the Cartridge Rubber Seal Seats, Seals and O-Ring

  • The bottom of the cartridge is what gets fouled from mineral deposits in the water.
  • Gently remove the rubber inlet seals with a screwdriver being careful not to damage the rubber seals.
  • Clean the seal seats in the bottom of the cartridge body with a soft nylon brush such as an old toothbrush and remove any calcification or sediment. Using a product like Lime-A-Way may help.
  • If the rubber seals are damaged or cannot be cleaned, then they need to be replaced.
  • As with replacement of a damaged cartridge described in the previous section, take the cartridge with you to the hardware store to ensure you buy the proper rubber seals.
  • If your faucet was leaking from the spout body neck, then you must remove the O-ring from the faucet body neck.Coat the new O-ring with a light coating of silicone plumbers grease and replace and install it by setting it in the groove on the faucet body.

Reassemble Disc Cartridge and Faucet

  • Next, reassemble the cartridge.
  • Replace the new or cleaned rubber seals back into their seal seats.
  • Place the disc cartridge back into the faucet body aligning the tabs on the cartridge with the notches in the faucet body.
  • Replace the decorative cover plate if there was one used in your faucet.
  • Replace the handle and tighten the attaching screw.

Restore Water Supply to Faucet

  • Restore the water supply to the faucet and check for leaks.
  • Set the faucet to the center open position.
  • Turn the water supply back on gradually and when air stops sputtering out of the faucet, turn the faucet to the closed position.