How to repair or replace a cartridge-type faucet stem to correct leaks from the spout or handles.
Most modern faucet stems are actually a cartridge with a few replaceable parts instead of the older faucets stems that had a washer and O-ring. Cartridge-type faucets are easy to work on as long as you have the parts for your cartridge. Due to their design, cartridge-type faucets usually leak right away instead of gradually dripping at an increasing rate so you may want to have a replacement cartridge and repair parts on hand. A cartridge-type faucet can be repaired for between $5 and $20 depending on whether you just need to replace the valve seat, O-rings, or the entire cartridge.
There are several types of faucets classified by how they control the flow of water. There are compression, ball, disc, and cartridge.
Compression faucets are the first type of faucet produced. They are still found in homes and can still be purchased. They are in expensive and the most prone to leaking. Compression faucets have a separate hot and cold water handle and the water flow is stopped by compressing the rubber washer against a brass or ceramic valve seat. The washer is held in place by a stainless steel or brass screw and as the washer wears away, the faucets leaks.
Ball faucets are usually found in kitchen sinks and were the first type of washerless faucet. They have a single handle which moves over a rounded ball shaped cap right above the base of the faucet spout. The plastic or metal ball has slots which line up with ports on the ball shaped cap to control the flow and temperature of the water. Since this type of faucet has many parts which can get clogged with dirt or scale, ball faucets tend to leak more than other washerless faucets.
Cartridge faucets use a stem that moves up and down within a cartridge to regulate flow. Unlike a ball faucet where the handle is pushed back to turn on the water, single handle cartridge faucets are controlled by pulling up on the handle to adjust water volume and a then turned left or right to adjust the temperature.
There are also two handle cartridge faucets that look similar to compression type faucets. You can determine which type you have by how the handles are used. A compression faucet requires you to tighten, compress, the washer to close the water flow. With a cartridge faucet, the action is smooth and consistent. The water flow is controlled within a quarter or half turn and once the water stops, you cannot tighten or turn the handle past this point.
Disc faucets are the newest type of faucet. They have a single lever and a wide cylindrical body. Inside the faucet there is a large cartridge which contains two ceramic discs that slide over each other to control the water.
Kitchen Cartridge-Type Faucet – Exploded view
Single-Handle Cartridge-Type Bathroom Faucet – Exploded view
Tools and Materials
Philips and flathead screwdrivers
Faucet stem grease
New cartridge and O-rings
New faucets are easy to take apart and replacement parts are available at most hardware stores, home centers and plumbing supply stores. The hardest part of the repair might be finding the correct repair kit or cartridge for your brand and style. disassemble the faucet, and take the parts along to assure a perfect match.
If your faucet leaks from the spout, replace the seats and springs. If it continues to drip from the spout after replacing the seats and springs, replace the cartridge, too. If your faucet leaks around the handles, the O-rings on the cartridge are bad. You can purchase a kit that includes a new cartridge and O-rings.
Leaks usually develop on the hot side since the water temperature accelerates deterioration and people tend to use the hot side more often. Since you will have the water off and your tools out you should replace parts on both hot and cold sides to save doing the same repair for the other side 6 months later.
1. Remove the handles and retraining nut
Shut off the water to the sink. Remove the faucet handles by removing the cover caps and removing the retaining screws. You may need a utility knife to pry off the cap and a Philips head screwdriver for the screws. Occasionally the handles are held in place with Allen screws so you would need an Allen wrench to remove the handle. After the handles are removed, unscrew the large nut that holds the cartridge.
2. Remove the cartridge and seat
Pull straight up on the cartridge to remove it. You may need to use pliers but protect the cartridge with tape or a rag. Another way to remove the cartridge is to reinstall the handle onto the top of the cartridge and tighten the screw. You can then pull the cartridge straight out. Make note of the orientation of the cartridge since many have notches so you can reinstall it the same way. Remove the old seat and spring with a small flathead screwdriver.
Some cartridges are also reversible, meaning that one stem can be used in either the hot or cold side. The cartridge can be reversed by removing a retaining clip at the top and the stem is turned 90 degrees and the clip reinserted.
3. Installing the new cartridge
Insert the new spring into the recess and push the new seat in with your finger. Spread a thin layer of plumber’s grease around the cartridge. Push the cartridge into the faucet, aligning it with the notches. Tighten the large retaining nut with the wrench and replace the handles.
With a few tools and the right parts you can correct a leaking cartridge-type faucet in under 20 minutes for under $20.