A ceramic disc faucet actually has two fire-hardened ceramic discs—an upper one that moves and a fixed lower one. The two discs move against each other in a shearing action, blocking water or allowing it to pass through. The seal between the two discs is watertight because they are polished to near-perfect flatness. Ceramic disc faucets were first made popular by high-end European faucet makers and now produced by American Standard, Kohler, Price Pfister, and many other American faucet manufacturers.
Ceramic disk faucets are nearly maintenance free and are generally guaranteed not to wear out. Ceramic valves are more durable over the long run in a broader variety of water conditions than any other variety of valve on the market.
The discs themselves have diamond-like hardness—they are impervious to line debris, mineral buildups, and other common problems that affect valve life.
If this type of faucet leaks, the culprits are usually the inlet and outlet seals or sediment buildup in the inlets. The handle should be in the “on” position when repairing a disc faucet to prevent cracking the replacement seals.
If a peeling from galvanized pipe or a small rock gets into the valve, it can score the surfaces, but these occurrences are rare. If a ceramic disc faucet drips, don’t try to force the handle closed—just flutter it back and forth a few times to dislodge any particles.
The range of control with a ceramic disc faucet varies. From full-off to full-on may require only a quarter or half turn; for a fuller adjustment range and greater flow, three-quarter-turn models are also available. In general, all washerless faucets offer very precise, ergonomic control. Even a child can turn one of these faucets off and on with one pinkie. They’re also good for people who have arthritis or who want something more decorative than a lever style.
Ceramic discs are popular because of their ease of use and reliability. Though competitively priced ceramic disc faucets are now available, ceramic discs that cost $100 or more are used primarily in mid-range and high-end installations. If a repair is ever needed, the entire ceramic disc cartridge is replaced, which runs from about $15 to $25.