How to Fix a Leaky Faucet: Cartridge, Compression, Ball and Ceramic Disc Repairs

Most leaky faucets are fixed by replacing one worn part: the rubber washer and seat in a two-handle compression faucet, or the cartridge, ball assembly, or ceramic disc in a single-handle faucet. Shut off the water at the stop valves under the sink, plug the drain so screws do not disappear, take the handle apart in order, replace the part that matches your brand and model, and reassemble. Call a plumber when the seat or valve body is damaged, parts are no longer made, the stop valves will not close, or the leak is coming from inside the wall.

A dripping faucet is the most common small plumbing job in an East Metro home, and it is one a careful homeowner can often do. This guide walks through the four faucet types, what fails on each, the fix, and the point where a repair stops being a homeowner job. It is written by a plumbing company in Woodbury that repairs faucets every week, so the “call a plumber” advice is honest about where the line actually is.

What kind of faucet do you have?

The fix depends on the type, so start here.

A compression faucet has two handles that you turn several times to open and close, and you can feel the handle tighten as it shuts off. Inside each handle is a stem with a rubber washer on the bottom that presses against a metal seat in the faucet body. These are the oldest design and are still common in older Woodbury, Stillwater, and St. Paul homes and in utility sinks.

A cartridge faucet can have one handle or two, and the handle moves smoothly to a stop without tightening. A cylindrical cartridge inside controls flow and, in single-handle versions, temperature. Most modern kitchen and bathroom faucets from Moen, Delta, Kohler, and similar brands are cartridge faucets.

A ball faucet is a single-handle faucet with a rounded cap under the handle. Inside is a slotted metal or plastic ball that sits on spring-loaded rubber seats. Older single-handle kitchen faucets are often this type.

A ceramic disc faucet is a single-handle faucet with a wide cylindrical body. Two ceramic discs slide against each other to control flow. They last a long time but are sensitive to grit and mineral scale.

If you are not sure, remove the handle and look. A stem with a washer means compression; a cylinder means cartridge; a ball means ball; a wide cylinder with ceramic plates means disc.

Why is my faucet dripping?

A drip from the spout when the handle is off means the sealing part is worn or scaled: the washer and seat on a compression faucet, the cartridge or ball seats on a single-handle faucet, or the discs on a ceramic disc faucet. A handle that has to be forced to stop the drip is the same problem one step further along, and forcing it scores the seat.

Water at the base of the spout or handle means a worn O-ring or a loose spout collar, not the sealing part. Water under the sink means a supply connection, a supply line, or a cracked faucet body, and that one gets fixed before anything else because it damages the cabinet.

Sputtering or low flow from one faucet while the rest of the house is fine is usually a clogged aerator or a cartridge packed with scale. Whole-house low pressure is a different problem entirely; see why one faucet has low pressure on our fixture page.

How do you fix a dripping compression faucet?

1. Shut off both stop valves under the sink and open the faucet to release pressure. Plug the drain.
2. Remove the decorative cap on the handle, then the handle screw and the handle.
3. Unscrew the packing nut and lift out the stem.
4. Remove the screw holding the washer on the bottom of the stem and replace the washer with an exact match. Replace the O-ring on the stem while it is out.
5. Look at the seat inside the faucet body with a flashlight. If it is pitted or rough, a new washer will not last; the seat needs to be replaced or ground smooth with a seat-dressing tool, and that is a reasonable point to call.
6. Reassemble, turn the water on slowly, and test.

How do you replace a faucet cartridge?

1. Shut off the stop valves and relieve pressure. Plug the drain.
2. Find the brand and, if you can, the model. It is often on the body or under the handle cap. Photograph the faucet before you start.
3. Remove the handle. Some use a set screw under a cap, some a screw on top.
4. Remove the retaining clip or nut that holds the cartridge, noting its orientation. Photograph it.
5. Pull the cartridge straight up. Scaled cartridges stick; a cartridge puller for that brand is worth using rather than prying with pliers, which can break the faucet body.
6. Install the matching new cartridge in the same orientation. Reversed cartridges give you hot on the cold side.
7. Reassemble and test. If the handle feels stiff, the cartridge is misaligned.

Ball faucets follow the same pattern with a repair kit that includes the ball, the rubber seats, and the springs; the springs and seats are what usually wear. Ceramic disc faucets rarely need a new cylinder; more often the inlet seals under the cylinder need cleaning or replacement, and grit or scale on the discs needs to be rinsed off.

What if the leak is at the base or under the sink?

A leak at the base of the spout on a kitchen faucet is a worn O-ring on the spout. Remove the spout, replace the O-rings, and reassemble. A leak under the sink is a supply connection: tighten a loose nut a quarter turn, or replace a supply line that is corroded or has a cracked braid. If the faucet body itself is weeping, the faucet is done and replacement is the fix.

Any time you are under the sink, check the stop valves. If one will not close fully, or drips from its stem when you turn it, have it replaced. A stop that will not shut off is what turns a faucet repair into a flooded cabinet the next time.

How does hard water shorten a cartridge’s life?

Calcium and magnesium in hard water come out of solution as scale, and scale collects wherever water sits or moves against a surface: on ceramic discs, in the ports of a cartridge, on compression seats, and inside aerators. Scale keeps sealing surfaces from meeting and grinds them as the handle moves. Municipal water across Woodbury and the East Metro is hard to very hard on the USGS scale, which is why faucet cartridges here can fail well before the years a manufacturer expects.

Two things help. Measure your hardness rather than guessing; our free basic water test does that at your tap. And if the reading is high and you are replacing cartridges and cleaning showerheads on a schedule, a properly sized softener is the fix for the cause rather than the symptom. Our water softener installation page covers when softening makes sense and what a plumber-installed softener includes.

When should you call a plumber?

Call when the compression seat is pitted and a washer does not hold. Call when the faucet body is corroded or cracked, or the finish is flaking into the cartridge. Call when the model is discontinued and no cartridge matches. Call when the stop valves will not close, when a cartridge is seized and the puller will not free it, or when the leak is behind the wall, which is a shower valve or a supply line rather than a faucet. And call when the whole house has low pressure, because that is a pressure reducing valve or a water service line problem that no faucet part will fix.

A.J. Alberts repairs and replaces faucets across Woodbury and the East Metro, and we quote the repair and the replacement side by side in writing so you can compare. See faucet repair and fixture installation for what a visit covers, or the plumbing services page for the rest of the work we do. If your toilet is running as well, our guide to how to fix a running toilet covers the flapper, fill valve, and flush valve the same way.

How much water does a dripping faucet waste?

More than it looks like. The EPA’s WaterSense program estimates that a faucet dripping at one drip per second wastes more than 3,000 gallons a year, and that the average household’s leaks add up to nearly 10,000 gallons a year. On the hot side, that is water you also paid to heat. A faucet repair usually pays for itself on the water bill before the year is out.

Faucet dripping in Woodbury, Oakdale, Cottage Grove, Stillwater, or anywhere in the East Metro? Call A.J. Alberts at 651-738-0580 or book online. Written price before the work, no commissioned salespeople.

Sources and Further Reading

• EPA WaterSense: Fix a Leak Week, how much water leaks waste
• EPA WaterSense: bathroom faucets and aerators
• USGS: hardness of water