A leaky faucet can be an expensive annoyance. Fortunately, basic faucet repair projects such as replacing a faucet stem are among the easier plumbing projects that a homeowner may need to undertake. Faucet stem repairs can usually be completed quickly and inexpensively, because replacing a faucet stem is mostly a matter of unscrewing several parts in succession and then replacing them in the same order.
Replacing a faucet stem is typically a rather straightforward repair. The water supply to the faucet should always be turned off before attempting to repair the faucet. The faucets should be opened to drain water from the lines after the water supply has been disconnected.
The faucet handle is usually attached with a screw, which is often concealed beneath a cap on the handle. This cap often bears the hot and cold markings. The cap usually can be removed by gently prying it with a small screwdriver, though some caps are threaded and will need to be carefully removed with pliers. Once the cap and screw have been removed, the faucet handle should lift off easily. Occasionally, if the handle is stuck because of corrosion, it may be necessary to use a special tool called a handle remover.
Once the handle has been removed, the next step is to loosen the locknut or packing nut with an adjustable crescent wrench. This packing nut should be visible on the faucet, though some faucets may have a decorative cap or bonnet that will need to be carefully removed first. After the packing nut has been removed, the stem can be removed from the faucet by threading it out. The stem will have a washer on the bottom that is attached with a screw. These stem washers wear over time and need to be replaced periodically.
It is a good idea while the stem is removed to inspect the valve seat where the stem washer contacts. The valve seat can be ground with a valve seat dresser if it appears to be rough or worn. Some valve seats may be removed and replaced using a valve seat wrench. Removable valve seats will have a square or hexagonal hole, or have a slot for a regular screwdriver.
The replacement faucet stem is installed by threading the stem back into the faucet. The packing nut should be hand tightened and then snugged down with a crescent wrench. The faucet may leak around the stem if the packing nut is too loose. The faucet will be difficult to turn if the packing nut is too tight.
It is a good idea to turn the water back on and check for leaks around the faucet stem before replacing any decorative covers or bonnets. The faucet handle can then be reattached. The faucet can now be tested for operation and leaks.
A stem faucet usually has two handles — one each for hot water and cold water. Some bathroom stem faucets may have three handles in the shower with the third handle serving to divert water from the tub spout to the shower head. Stem faucets are also called compression faucets or washer-type faucets. Most stem faucets are quite similar, whether it is a bathroom faucet, a kitchen faucet, an outdoor faucet, or even a bar faucet.
Washerless faucets usually have one handle. These faucets use a ball or cartridge system that is often replaced as a unit. Washerless faucets are constructed differently than stem faucets and use a ball or cartridge in place of a stem.
Determining in advance which faucet parts will be needed can be a challenge. It is often easiest to remove the defective faucet stem and bring it to a hardware or plumbing supply store to obtain a match. There are many different faucet stems available and even a slight difference in parts can prevent the faucet from working properly.