A faucet usually leaks because a part inside it has worn out, become loose, or no longer seals properly. Common causes include a worn washer, damaged O-ring, faulty cartridge, loose plumbing connections, mineral buildup, or high water pressure. Many of these problems are inexpensive to fix, but some may require a plumber if the leak involves damaged pipes or internal faucet components.
A dripping faucet is more than just an annoying sound. Even a slow drip can waste a significant amount of water over time, increase your utility bill, and lead to water damage if it’s ignored. Moisture around the sink can also encourage mold growth and damage cabinets, countertops, or flooring.
The good news is that most faucet leaks are caused by common issues that are easy to identify. In many cases, replacing a small part is all it takes to stop the leak and restore your faucet to proper working order.
In this guide, we’ll explain the seven most common reasons a faucet leaks, show you how to identify the source of the problem, and walk you through the best repair options. You’ll also learn when a simple DIY fix is enough and when it’s time to call a professional plumber.
What Causes a Faucet to Leak?
A faucet leaks when one or more of its internal parts wear out, become damaged, or fail to create a watertight seal. Over time, everyday use causes components like washers, O-rings, cartridges, and seals to wear down. Hard water, mineral buildup, corrosion, and high water pressure can also shorten the life of these parts and lead to leaks.
The location of the leak is often the best clue to what’s causing the problem. For example, a faucet dripping from the spout is usually caused by a worn washer or faulty cartridge, while a leak around the handle often points to a damaged O-ring. Water under the sink is more likely to be caused by a loose supply line or a leaking plumbing connection.
Common places where a faucet may leak include:
- The faucet spout
- Around the faucet handle
- The base of the faucet
- Under the sink
- Water supply lines or shut-off valves
Identifying where the water is coming from is the first step toward fixing the problem. Once you pinpoint the source of the leak, it’s much easier to determine whether you need a simple replacement part, a faucet repair, or help from a professional plumber.
7 Common Causes of a Leaking Faucet
Most faucet leaks are caused by worn or damaged parts that can often be repaired without replacing the entire faucet. Identifying the cause of the leak is the first step toward choosing the right repair and preventing further water damage.
Below are the seven most common reasons a faucet leaks and how to fix each one.
1. Worn-Out Washer
A worn washer is one of the most common causes of a faucet dripping from the spout. This issue is especially common in older compression faucets, which use a rubber washer to create a watertight seal every time the handle is turned off.
After years of daily use, the washer can become flattened, cracked, or worn. When that happens, it can no longer seal properly, allowing water to continue dripping from the spout even when the faucet is fully closed.
Common signs include:
- Constant dripping from the faucet spout
- The leak gradually gets worse over time
- The faucet is an older compression-style model
How to fix it:
Turn off the water supply, remove the faucet handle, and replace the worn washer with a new one of the same size. In most cases, this inexpensive repair is all that’s needed to stop the leak.
2. Damaged O-Ring
A damaged O-ring is a common reason for water leaks around the faucet handle. The O-ring is a small rubber seal that prevents water from escaping where the handle connects to the faucet body.
Like other rubber components, the O-ring can wear out, crack, or become brittle over time. Once it loses its flexibility, water can leak around the handle whenever the faucet is turned on.
Common signs include:
- Water is leaking around the faucet handle
- Leaks that appear only while the faucet is running
- A cracked, flattened, or worn rubber O-ring
How to fix it:
Replace the damaged O-ring with one that matches the original size and material. Installing the correct replacement creates a proper seal and usually stops the leak without replacing the entire faucet.
3. Faulty Cartridge
A worn or damaged cartridge is one of the most common causes of leaks in cartridge-style faucets. The cartridge controls both the flow of water and the temperature. As it wears out, it may no longer create a proper seal, allowing water to leak from the spout, the handle, or both.
Over time, normal use, hard water, and mineral buildup can damage the cartridge and affect how smoothly the faucet operates.
Common signs include:
- Water dripping from the spout
- Leaks around the faucet handle
- Difficulty adjusting the water temperature
- A stiff or hard-to-turn faucet handle
How to fix it:
Turn off the water supply, remove the old cartridge, and install the exact replacement recommended by the faucet manufacturer. Using the correct cartridge is important, as different faucet models require specific replacement parts.
4. Corroded Valve Seat
A corroded valve seat can keep your faucet from sealing completely, causing it to drip even when it’s turned off. The valve seat connects the faucet body to the spout and plays an important role in creating a watertight seal.
Over time, hard water and mineral deposits can cause the valve seat to corrode or become rough. This prevents the washer or cartridge from sealing properly, allowing water to continue leaking from the spout.
Common signs include:
- A slow, steady drip from the faucet spout
- Mineral deposits or corrosion around the faucet
- An older faucet or plumbing system
- The leak continues after replacing the washer
How to fix it:
If the corrosion is minor, cleaning the valve seat may restore a proper seal. If it’s badly worn or damaged, replacing the valve seat is usually the most effective long-term solution. Regular maintenance can also help prevent mineral buildup from causing the problem again.
5. Loose or Worn Seals
Loose seals or worn gaskets can cause water to leak around the base of the faucet or other connection points. These rubber seals help prevent water from escaping, but they gradually wear out due to daily use, constant water pressure, and age.
When the seals no longer fit tightly, water can seep out whenever the faucet is running, eventually causing moisture damage around the sink if left unrepaired.
Common signs include:
- Water pooling around the base of the faucet
- Small leaks while the faucet is running
- Moisture around the mounting hardware
- Water is collecting on the countertop near the faucet
How to fix it:
Inspect the seals and gaskets for wear or damage. Replacing worn seals or tightening loose mounting hardware is often enough to stop the leak before it causes water damage beneath the sink.
6. High Water Pressure
High water pressure can cause a faucet to leak by putting extra stress on its internal seals and valves. When the pressure is too high, the faucet may not shut off completely, allowing water to drip even when the handle is fully closed.
This type of leak often appears at certain times of the day, especially late at night or early in the morning when household water use is low, and water pressure naturally increases.
Common signs include:
- The faucet drips only at certain times
- Multiple faucets in the home have similar leaks
- Water flows very forcefully from the faucet
- Banging or knocking noises in the plumbing system
How to fix it:
A licensed plumber can test your home’s water pressure with a pressure gauge. While excessive pressure can cause faucet leaks, low water pressure can also indicate underlying plumbing problems that should be inspected. If the pressure is higher than the recommended range, installing or adjusting a pressure-reducing valve (PRV) can help protect your plumbing system and stop pressure-related leaks.
7. Loose or Damaged Plumbing Connections
Leaks under the sink are often caused by loose supply lines or damaged plumbing connections rather than the faucet itself. Water supply hoses, compression fittings, and shut-off valves can loosen over time or develop leaks due to corrosion and normal wear.
Because these leaks occur below the sink, they’re sometimes mistaken for a leaking faucet when the real problem is in the plumbing connections.
Common signs include:
- Water is collecting inside the cabinet under the sink
- Wet or dripping supply hoses
- Leaks around the shut-off valves
- Moisture around compression fittings or pipe connections
How to fix it:
Start by checking whether the supply line connections are loose and tighten them carefully if needed. If the supply hose, shut-off valve, or fitting is corroded, cracked, or damaged, replacing the affected part is the safest and most reliable solution.
If you’re unable to identify the source of the leak, contact a licensed plumber to prevent further water damage. Hidden plumbing leaks behind walls or beneath cabinets can sometimes appear to be a leaking faucet.
How to Identify Where Your Faucet Is Leaking
The location of the leak is one of the best clues to what’s causing your faucet to leak. Before you take the faucet apart, inspect it carefully while it’s both on and off. Identifying where the water is coming from can help you pinpoint the problem and determine whether it’s a simple DIY repair or a job for a professional plumber.
Use the table below to match the leak location with the most likely cause.
| Leak Location | Most Likely Cause |
| Faucet spout | Worn washer, faulty cartridge, or corroded valve seat |
| Around the handle | Damaged O-ring or worn cartridge |
| Base of the faucet | Worn gasket, loose seal, or damaged O-ring |
| Under the sink | Loose supply line, shut-off valve, or plumbing connection |
| Around the valve body | Loose fittings or worn internal seals |
Keep in mind that some leaks may have more than one cause. For example, an older faucet may have both a worn cartridge and deteriorated seals. If replacing the most likely faulty part doesn’t stop the leak, inspect the other components before assuming the entire faucet needs to be replaced.
Once you’ve identified the source of the leak, you can choose the correct repair, avoid replacing unnecessary parts, and restore your faucet to proper working condition more quickly.
How to Stop a Leaking Faucet
The best way to stop a leaking faucet is to identify the cause of the leak and replace the worn or damaged part. Many common faucet leaks can be repaired with basic tools and a few replacement parts. However, if the leak is caused by internal damage or a plumbing issue, you may need the help of a licensed plumber.
Follow these steps to repair a leaking faucet.
1. Turn Off the Water Supply
Start by shutting off the water before taking the faucet apart. Locate the hot and cold shut-off valves under the sink and turn them clockwise until they’re fully closed. Then, open the faucet to drain any remaining water and relieve pressure in the lines.
2. Identify Your Faucet Type
Knowing your faucet type helps you choose the correct replacement parts. Different faucet designs use different internal components, so identifying the model before starting the repair is important.
The most common faucet types are:
- Compression faucet
- Ball faucet
- Cartridge faucet
- Ceramic disc faucet
If you’re unsure which type you have, check the manufacturer’s manual or look up the model number online.
3. Inspect the Internal Components
Remove the faucet handle and inspect the parts for signs of wear or damage. Look closely at the washer, O-ring, cartridge, seals, springs, and other internal components.
Check for:
- Cracked or worn rubber parts
- Mineral buildup
- Corrosion
- Broken or loose components
- Damaged seals
Finding the damaged part before buying replacements can save both time and money.
4. Replace Worn Parts
Replace any worn or damaged components with parts designed for your faucet model. In many cases, installing a new washer, O-ring, cartridge, or gasket is enough to stop the leak.
Whenever possible, use manufacturer-approved replacement parts to ensure a proper fit and long-lasting repair.
5. Reassemble the Faucet and Test It
Reassemble the faucet carefully and test it before considering the repair complete. Turn the water supply back on slowly and let the faucet run for several minutes.
Check for:
- Drips from the spout
- Leaks around the handle
- Water around the base
- Leaks under the sink
- Proper hot and cold water operation
If the faucet no longer leaks, the repair was successful.
If water continues to leak after replacing the worn parts, the faucet may have internal damage, severe corrosion, or another plumbing problem that requires professional diagnosis. In that case, contacting a licensed plumber can help prevent further water damage and ensure the issue is repaired correctly.
Can You Fix a Leaking Faucet Yourself?
Yes, you can fix many leaking faucets yourself if the problem is caused by a worn or damaged part. Simple repairs such as replacing a washer, O-ring, or cartridge can often be completed with basic hand tools, making them manageable for many homeowners.
DIY repairs are usually a good option for:
- Replacing a worn washer
- Installing a new O-ring
- Replacing a faulty faucet cartridge
- Tightening loose supply line connections
- Cleaning mineral buildup from faucet components
Before starting the repair, always turn off the water supply and use replacement parts that match your faucet’s make and model. Following the manufacturer’s instructions can also help ensure the repair is completed correctly.
However, not every faucet leak is a simple fix. Some problems involve damaged plumbing or internal components that require professional tools and experience.
It’s best to call a licensed plumber if:
- The faucet body is cracked or damaged
- Pipes or plumbing connections under the sink are leaking
- The faucet continues to leak after replacing worn parts
- You find severe corrosion inside the faucet
- The shut-off valves won’t close completely
- Multiple faucets or plumbing fixtures are leaking at the same time
If you’re unsure about the cause of the leak or don’t feel comfortable taking the faucet apart, it’s safer to have a professional inspect it. A plumber can identify the problem, make the necessary repairs, and help prevent water damage or more expensive plumbing issues down the road.
When Should You Replace a Leaking Faucet Instead of Repairing It?
You should replace a leaking faucet when repairs are no longer cost-effective or the faucet is too old or damaged to function reliably. While many leaks can be fixed by replacing a washer, cartridge, or O-ring, repeated repairs can become more expensive than installing a new faucet.
Consider replacing your faucet if:
- It continues to leak even after multiple repairs.
- The faucet body is cracked, broken, or heavily corroded.
- Replacement parts are no longer available.
- The faucet is 15 to 20 years old or older.
- Repair costs are close to the cost of a new faucet.
- You want a more water-efficient or updated fixture.
Replacing an outdated faucet can also improve your home’s appearance and performance. Many modern faucets are designed to use less water without sacrificing water pressure, helping you conserve water and reduce utility costs.
If you’re unsure whether to repair or replace your faucet, compare the total repair cost with the price of a new fixture. If the faucet has recurring problems or significant wear, replacement is often the better long-term investment. A new faucet can provide greater reliability, improved efficiency, and fewer plumbing issues for years to come.
How to Prevent Faucet Leaks
Regular maintenance is the best way to prevent most faucet leaks and extend the life of your plumbing fixtures. A few simple habits can reduce wear on internal components, improve your faucet’s performance, and help you avoid costly repairs in the future.
Here are some practical ways to prevent faucet leaks:
- Avoid turning faucet handles too tightly, as excessive force can wear out washers and seals.
- Replace worn washers, O-rings, and cartridges as soon as they show signs of damage.
- Clean mineral deposits regularly, especially if your home has hard water.
- Inspect under the sink periodically for loose supply line connections or signs of moisture.
- Keep your home’s water pressure within the recommended range to reduce stress on faucet components.
- Repair small leaks promptly before they lead to bigger plumbing problems or water damage.
- Schedule routine plumbing inspections if you have an older home or aging plumbing system.
Taking care of your faucet doesn’t require much time, but it can save you money in the long run. Preventive maintenance helps your faucet last longer, reduces water waste, and lowers the risk of unexpected leaks that can damage cabinets, countertops, and flooring. Fixing minor issues early is almost always less expensive than repairing water damage caused by a leak that’s been ignored.
Final Thoughts
Most faucet leaks can be fixed quickly once you identify what’s causing the problem. In many cases, replacing a worn washer, O-ring, cartridge, or seal is all it takes to stop the leak and restore your faucet’s performance.
The key is to address the problem as soon as you notice it. Even a small drip can waste water, increase your utility bill, and eventually lead to water damage, mold growth, or damage to your cabinets and countertops if left untreated.
Many homeowners can handle basic faucet repairs with a few tools and the right replacement parts. However, if the leak continues after replacing worn components, or you find corrosion, damaged pipes, or leaks under the sink, it’s best to contact a professional for plumbing repair services. A professional can identify the root cause of the problem and recommend the most effective repair.
Fixing a leaking faucet early is one of the simplest ways to protect your plumbing system and avoid more expensive repairs later. Regular maintenance and prompt attention to small leaks can help keep your faucets working efficiently for years to come.
Frequently Asked Questions
Why is my faucet dripping even when it’s turned off?
A faucet usually drips after it’s turned off because one of its internal parts has worn out or no longer seals properly. Common causes include a worn washer, damaged O-ring, faulty cartridge, or corroded valve seat. Replacing the damaged component is often enough to stop the leak.
Why is my faucet leaking from the handle?
A faucet that leaks from the handle is commonly caused by a worn O-ring or a faulty cartridge. These parts create a watertight seal around the handle and control water flow. When they wear out, water can escape around the handle during use.
Why is my faucet leaking at the base?
A leak at the base of a faucet is usually caused by a worn gasket, damaged O-ring, or loose mounting hardware. Replacing the worn seal or tightening the faucet can often fix the problem before it causes water damage around the sink.
Can high water pressure cause a faucet to leak?
Yes, high water pressure can cause a faucet to leak by putting extra strain on its internal seals and valves. If the pressure in your home is too high, installing or adjusting a pressure-reducing valve (PRV) can help protect your plumbing fixtures and prevent future leaks.
Can I fix a leaking faucet myself?
Yes, many leaking faucets can be repaired as a DIY project. Replacing a washer, O-ring, cartridge, or tightening a loose connection is often straightforward with basic tools. However, if the leak is caused by damaged pipes, severe corrosion, or continues after repairs, it’s best to call a licensed plumber.
Should I repair or replace a leaking faucet?
Repairing a faucet is usually the best option when only a single part has failed. However, if the faucet is old, heavily corroded, or continues to leak after multiple repairs, replacing it is often the more cost-effective and reliable solution.
How much water does a dripping faucet waste?
A dripping faucet can waste a significant amount of water over time. Even a slow drip can waste hundreds or even thousands of gallons of water each year, increasing your utility bill and wasting a valuable natural resource.
How much does it cost to repair a leaking faucet?
The cost of repairing a leaking faucet depends on the source of the leak and the parts that need to be replaced. Simple repairs, such as replacing a washer or O-ring, are generally inexpensive. More complex repairs, such as replacing a cartridge or fixing plumbing connections, typically cost more. If repair costs approach the price of a new faucet, replacement may be the better long-term choice.
