When stem faucets develop a leak, the problem is usually easy to fix. Most often, it’s a drip from the spout or a leak around the base.

But what are they? To the beginner, a faucet is just a faucet. But there are three basic types. Let’s learn the differences and how to identify.

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What are Faucet Stems?

The stem is all the moving parts within a faucet. It has different functions, including how much hot and cold water you receive, and lets you change the water’s temperature. Each handle has its own stem assembly.

Plumbers often identify faucets by the type of stem system they use. That’s why, in general, they’re often referred to as “stem faucets.”

The Difference Between Stem & Cartridge

You might have heard a stem faucet referred to as a cartridge faucet. Although they are considered to be the same by most people, they’re actually different.

A stem is used in two-handle faucets, where one handle is responsible for cold water and the other is responsible for hot water. A cartridge is used in faucets to control hot and cold water through just one handle. It can be repaired quite easily. However, a broken or leaking cartridge should be replaced, not repaired.

Let’s talk about the three different types next.

What are Stem Faucets?

Before you make a faucet repair, the first step is to identify the type of stem faucet you have. Here are the three common types:

1. Seat-And-Washer Stem Faucets

The seat-and-washer faucet, also called a compression faucet, is the most common type of faucet, especially in older homes. Seat-and-washer faucets have separate hot and cold controls (two handles; one for hot and one for cold).

In the “OFF” (closed) position, the stem compresses a washer into a beveled seat located inside the base. This stops the flow of water. The reverse of this process happens when the handle is in the “ON” (open) position, allowing water to flow out.

seat and washer compression stem faucets diagram — Seat-and-washer style diagram

2. Diaphragm Stem Faucets

A diaphragm is another type of two-handle stem faucet. But instead of a washer, it uses a diaphragm. The diaphragm faucet uses a durable diaphragm in lieu of a resilient washer.

diaphragm stem faucets diagram — Diaphragm style diagram

3. Cartridge Stem Faucets

The cartridge faucet is technically not a stem faucet, although it’s often called that. Unlike a stem (which compresses up and down), a cartridge rotates to control water flow. And instead of a resilient washer or diaphragm, it uses a rubber seal and O-rings.

As noted above, the cartridge controls the flow (on or off) and temperature of both hot and cold water using just one handle. It is a more complex part than a traditional stem, so replacing it is your best course of action if it breaks down.

cartridge stem faucets diagram — Cartridge style diagram

Repairing Stem Faucets

As a washer wears out, you will find yourself having to apply more and more pressure to turn off the unit. That’s when dripping usually begins.

Repair techniques and methods vary from faucet to faucet, but in most cases, you can easily do it yourself. When buying replacement parts, take the old unit to the store. If the faucet cannot be repaired, it’s easy to replace it with a new one. We have articles below under “Related Resources” to help you with this process.

Final Thoughts

At first, you’ll find all these different terms confusing. But trust me, once you begin working with them, you’ll soon recognize the differences and begin remembering the names. I hope this article helps clear up some of the mystery.

Call 1-Tom-Plumber

Don’t hesitate to contact us here or call us at 1-Tom-Plumber (1-866-758-6237) if you would like help with your kitchen, bath, or shower stem faucet repair or replacement.

1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbing, drain cleaning, or water damage problem. We also handle the excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even on holidays.

What Are Stem Faucets (And How Do I Identify Them)?

What are Faucet Stems?

The Difference Between Stem & Cartridge