How To Fix a Leaky Single-handle Disk Faucet
Prevent Mold, Water Damage, and Increased Water Costs With a Simple Repair
Repairing a leaky bathroom or kitchen faucet is generally not a hard job, but it is sometimes complicated by the fact that there are so many different faucet designs, each with different types of parts and requiring different repair methods. Many single-handle faucets use some form of interior ball or cartridge. Most of the time, fixing a leaky single-handle faucet is a fairly simple matter of replacing the faucet cartridge or replacing the ball or its parts.
A single-handle disk faucet, however, uses a different design that requires a different repair procedure.
Identifying a Disk Faucet
From the outside, the disk, cartridge, and ball faucets look similar. Like most cartridge or ball faucets, a disk faucet usually has one handle (though there are some double-handle models). However, if you are facing fixing a leaky old-fashioned faucet, for example, it is not a disc faucet but rather it has compression valves, which is a much different and easier fix. But while ball faucets have a handle that rotates freely in all directions, a ceramic disk faucet has a distinctive operating motion that includes a smooth forward-back action, along with a left-right rotation. This is similar to the way standard cartridge faucets move, but you'll notice that a ceramic disk faucet has a shorter, wider body, not the upright cylindrical shape common to cartridge faucets.
Inside the faucet body, a disk faucet uses a special type of sealed cartridge with two closely fitting ceramic disks, one fixed, the other moveable. Moving the handle slides the disks around within their cartridge, aligning the holes in various ways to change the ratio of hot and cold water getting through the disks to the faucet's mixing chamber. It is a very dependable design that requires less attention than standard ball-type or cartridge faucets.
Before You Begin
In this project, we describe how to disassemble and clean the parts of a typical single-handle ceramic disk faucet. It is the same repair process if you have a single-handle kitchen faucet with a spray hose. In many cases, a simple cleaning of the seals and water ports will fix a faucet that is leaking. Sometimes, though, a simple cleaning will fail to fix the leaky faucet. In this case, the problem causing a single-handle faucet to leak may be damaged seals that have lost their resiliency.
Unlike other faucets, where seals, springs, and other parts are often offered in repair kits specified for particular faucet models, the seals for most ceramic disk faucets are not sold this way. Nor will you find suitable seals in the universal kits that offer a wide selection of washers, seals, and O-rings. If you find that the seals on your ceramic disk cartridge are cracked or badly worn, the fix is generally to just buy a new cartridge and install it.
What You'll Need
Equipment / Tools
- Allen (hex) wrench
- Channel-type pliers or pipe wrench
- Utility knife
- Old toothbrush or small nylon brush
- Replacement disk cartridge (if needed)
- New O-ring for faucet body
- Heatproof silicone plumber's grease
How To Fix a Leaky Single-handle Disk Faucet
Turn off the Water
The first step in faucet repair is to locate the hot and cold fixture shutoff valves and turn them off. The shutoffs are usually found directly under the sink, at the point where the water supply pipes are connected to the flexible water supply tubes leading up to the faucet tailpieces. Some valves have knurled knobs that are rotated clockwise to shut off the water, while others are lever-type valves with handles that rotate one-quarter turn to shut them off.
You do not need to turn off the home's main water supply to fix this problem. However, if your faucet does not have dedicated fixture shutoff valves, then you'll need to shut off the water supply to the entire house at a branch valve or at the main shutoff valve.
Once the water is shut off, open the faucet to release pressure and let the water drain out.
Remove the Faucet Handle
Detach the faucet handle from the faucet body and cartridge. The mounting screw is often concealed under a plastic or metal cap that covers the top of the faucet body, as shown here. If your faucet does not have a plastic cap, the handle may be attached by a hex screw on the side, front, or rear of the handle. Use a Phillips screwdriver or Allen wrench to remove the mounting screw, then gently pull or pry the handle off.
Remove the Disc Cartridge
With the handle removed the disk cartridge is now exposed and can be removed. Some styles have screws or a mounting ring that hold the disk cartridge in place. If you have this style, remove the screw or ring that secures the cartridge before lifting the cartridge out. If the cartridge is sticky, hold the stem with pliers to gently tug it out.
With the cartridge removed, check it for damage. If it is cracked or otherwise damaged, it will need to be replaced. If you have to replace a cartridge, it’s a good idea to bring the old one along to the hardware store, as it makes finding a replacement much easier.
Remove the Seals and Clean the Ports
The next steps may vary slightly, depending on the faucet's model and manufacturer. In most cases, disk faucets leak because rubber seals in the bottom of the ceramic disk get damaged or layered with grit or mineral deposits.
Inspect the bottom of the cartridge, and remove the rubber seals from the water inlet ports using a small screwdriver. Be careful not to damage the seals. Use a soft nylon brush (an old toothbrush works well) to gently clean the rubber seals.
Also, clean the ports at the bottom of the cartridge. If the ports have a substantial build-up of calcium, a product such as Lime-A-Way may help dissolve the deposits.
Replace the Spout O-Ring
Remove the O-ring from the faucet body neck. Coat a new O-ring with a light layer of silicone plumber's grease and install it by setting it into the groove on the faucet body.
Reassemble the Faucet
Insert the cleaned rubber seals back into their seal seats. Place the disk cartridge back into the faucet body, aligning the tabs on the cartridge with the notches in the faucet body. If there is a mounting screw or cap, reinstall it.
Attach the handle, then replace the decorative cap (if present). Tighten up the mounting screw of the single-handle faucet just enough until you feel resistance, but don't strip the screw.
Restore the Water Supply
Set the faucet handle to the center open position, then turn the water supply back on gradually. When air stops sputtering out of the faucet, move the handle to the closed position. Check to make sure the faucet is not leaking. If it's still leaking you may need to slightly tighten or adjust the inner parts.
How do I know if my faucet cartridge is bad?
There are distinct signs indicating you have a bad faucet cartridge. You will spot water leaking from the handle. The lever may not work well and it will feel different when you use it. In addition, you may have trouble regulating the water temperature.
What happens if you don't fix a dripping tap?
A leaking faucet should be repaired immediately because the problem will only get worse. You will have pools of leaking water in places you can't see and the trapped moisture will cause mold, mildew, and rot to develop.
How much does it cost to replace a faucet cartridge?
It can cost the price of the cartridge if you do it yourself. If you hire a plumber to fix a leaky faucet, you could be charged anywhere from $200 to $300, depending on where you live.