Why Is My Bathroom Faucet Leaking at the Base? Common Causes and Fixes

by Cody Gyale · February 16, 2025

A leaking bathroom faucet can be frustrating and wasteful. If you notice water pooling around the base of your faucet, you might wonder, Why is my bathroom faucet leaking at the base? This issue can lead to water damage, mold growth, and increased water bills if not fixed.

In this article, we’ll explore the most common causes of a leaking bathroom faucet and provide easy-to-follow solutions to fix it. Whether you’re a DIY enthusiast or just trying to avoid calling a plumber, this guide will help you stop the leak and keep your faucet in top shape.

Table of Contents

How does a Bathroom Faucet work?

Before fixing a leak, it’s good to understand how your bathroom faucet works. A faucet is a simple but important part of your sink. It controls how much water comes out and whether it’s hot or cold.

Most bathroom faucets have a few main parts:

Handle(s): This controls the water flow and temperature. A single-handle faucet moves up and down to turn the water on and off and side to side to adjust the temperature. A two-handle faucet has separate controls for hot and cold water.
Spout: This is the part where water comes out and flows into the sink.
O-rings: These are small rubber rings inside the faucet that help stop leaks. Over time, they wear out and need to be replaced.
Cartridge or Washer: This part opens and closes when you turn the handle, controlling the water flow. Some faucets use a cartridge, while others have a washer that stops or allows water to pass through.
Mounting Nuts & Screws: These parts hold the faucet in place on the sink. If they become loose, the faucet might wiggle or leak.

Signs That Your Faucet Is Leaking at the Base

A small leak might not be obvious at first, but over time, it can cause bigger problems. If you notice any of these signs, your faucet might be leaking at the base:

Water pooling around the base of the faucet: You might see small puddles of water forming around the bottom of the faucet, especially after using it. If you wipe it dry and the water comes back, there’s likely a leak.
Dampness or water stains on the countertop: If the area around your faucet always feels damp, or if you see dark spots, rings, or discoloration on the countertop, water is likely leaking from the faucet base.
Mold or mildew near the faucet: Constant moisture from a leak can lead to mold or mildew growth. You might see black, green, or white spots around the base of the faucet, sink, or nearby backsplash.
A musty smell around the sink: If you notice a damp or musty smell in your bathroom, it could be caused by hidden mold or mildew growing due to a slow leak.
Higher water bills due to wasted water: Even a small, steady leak can waste a surprising amount of water over time. If your water bill seems higher than usual and you haven’t changed your water usage, a leaking faucet could be the reason.

If you notice any of these signs, it’s important to inspect your faucet as soon as possible. A small leak might seem harmless, but over time, it can cause water damage, encourage mold growth, and lead to expensive repairs. Fixing the problem early can save you time and money.

Common Causes of a Leaking Faucet Base

A faucet leak at the base can happen for different reasons. Here are the most common causes and why they lead to leaks:

1. Worn-Out O-Rings

O-rings are small rubber rings inside the faucet that help stop water from leaking out. They create a tight seal between different faucet parts. Over time, these rings wear out because of constant use and exposure to water. If the O-rings crack, dry out, or become too loose, water can start leaking from the base of the faucet. This is one of the most common causes of leaks, and replacing O-rings is usually an easy fix.

2. Loose or Damaged Faucet Body

The faucet body is the main part of the faucet that connects to the sink. If it’s not tightly secured, water can seep through small gaps around the base. A loose faucet might also cause other internal parts to move out of place, making the leak worse. Over time, normal use of the faucet—like turning the handle or moving a swivel spout—can slowly loosen the mounting nuts that hold it in place. Tightening these parts can often solve the issue.

3. Clogged or Worn-Out Cartridge

The faucet cartridge is a small piece inside the faucet that controls water flow when you turn the handle. If it gets clogged with dirt, minerals, or debris, it might not work properly, leading to leaks. A worn-out cartridge can also cause water to escape where it shouldn’t, including at the base of the faucet. Replacing the cartridge is usually a simple fix, but cleaning it with vinegar can sometimes remove buildup and restore its function.

4. Improper Installation

If your faucet wasn’t installed correctly, leaks can start soon after it’s put in place. For example, if parts aren’t aligned properly or if the mounting nuts are too loose, water can escape. On the other hand, if parts are tightened too much, it can damage seals and O-rings, leading to leaks. If your faucet has been leaking since it was first installed, improper installation could be the problem.

5. Water Pressure Issues

If your home has high water pressure, it can wear out faucet seals faster. When water is forced through the faucet too strongly, it puts extra strain on the O-rings, washers, and other seals. Over time, these parts may break down, causing leaks. If you suspect high water pressure, you can test it using a water pressure gauge or check with a plumber. A pressure regulator might help prevent future faucet problems.

By identifying the cause of your leaking faucet, you can choose the right solution and prevent bigger plumbing issues. Most of these problems can be fixed with simple repairs, so don’t wait too long to take action!

Tools and Materials You’ll Need to Fix the Leak

Before you start fixing your leaking faucet, it’s important to have the right tools and materials ready. Having everything on hand will make the job easier and faster. Here’s what you’ll need:

Adjustable Wrench: This tool helps you loosen and tighten nuts and bolts on the faucet. It’s useful for taking apart and putting the faucet back together.
Screwdrivers (Phillips and Flathead): You’ll need these to remove the handle and other parts of the faucet. A Phillips screwdriver has a cross-shaped tip, and a flathead screwdriver has a straight tip.
Plumber’s Grease: A special grease that helps keep O-rings and other rubber parts in good condition. It also makes it easier to put parts back together and helps prevent future leaks.
Replacement O-Rings: These small rubber rings help seal the faucet and stop leaks. If your faucet is leaking at the base, worn-out O-rings are often the cause.
Replacement Faucet Cartridge (if needed): If your faucet cartridge is clogged or worn out, replacing it can stop leaks and improve water flow. Make sure to buy the correct cartridge for your faucet model.
Plumber’s Tape (Teflon Tape): This thin, white tape wraps around threads on faucet parts to create a tight seal and prevent leaks.
Towel or Sponge: You’ll need a towel or sponge to soak up any water that leaks out when you take the faucet apart. It also helps keep your workspace dry and clean.

Optional Items That May Help

Bucket or Small Container: Placing a bucket under the sink can catch any dripping water when you turn off the supply.
Needle-Nose Pliers: These can help remove small parts, like O-rings, if they’re stuck.
White Vinegar and an Old Toothbrush: If your faucet has buildup from hard water, vinegar and a toothbrush can help clean parts before reassembly.

Once you have all these tools and materials ready, you’ll be set to start fixing your faucet and stop the leak!

How to Fix a Faucet Leaking at the Base

If your bathroom faucet is leaking at the base, don’t worry! You can fix it yourself with some basic tools and a little patience. Follow these simple steps to stop the leak and get your faucet working like new.

Step 1: Turn Off the Water Supply

Before you do anything, you need to turn off the water. Look under your sink for two small valves—one for hot water and one for cold water. Turn them clockwise until they are fully closed. This will stop water from flowing to the faucet.

If you can’t find these valves, you’ll need to turn off the main water supply to your house. This is usually located in the basement, garage, or outside near your water meter. Turn the main valve off to stop water from running anywhere in your home.

Once the water is off, turn on the faucet to let any remaining water drain out.

Step 2: Remove the Handle and Spout

Now, you need to take apart the faucet so you can check the internal parts.

Use a screwdriver (either flathead or Phillips, depending on your faucet) to remove the screw holding the handle in place. Some faucets have a small cap covering the screw—you may need to pry it off with a flathead screwdriver.
Once the screw is removed, gently pull the handle off. If it’s stuck, wiggle it back and forth while pulling.
If your faucet has a spout that lifts off, remove it by pulling it up carefully. Some models may have a retaining screw that needs to be removed first.

Step 3: Inspect and Replace the O-Rings

O-rings are small rubber rings that prevent leaks by sealing gaps inside the faucet. Over time, they can wear out, crack, or dry out, allowing water to escape.

Look inside the faucet where the spout was attached. You should see one or more black rubber rings (O-rings).
Check if they are cracked, broken, or feel stiff. If they look damaged, they need to be replaced.
Carefully remove the old O-rings using a small flathead screwdriver or needle-nose pliers.
Get new O-rings that match the old ones. You can find them at a hardware store or online—just bring the old ones with you to get the right size.
Before putting the new O-rings in place, apply a small amount of plumber’s grease. This helps them fit better and last longer.
Slide the new O-rings into position, making sure they fit snugly.

Step 4: Check and Tighten the Faucet Body

If the faucet body is loose, water can leak out from the base.

Look underneath the sink and find the mounting nuts that hold the faucet in place.
Use an adjustable wrench to tighten the nuts, but be careful not to over-tighten them, as this could crack the sink or damage the faucet.
Also, check if any other screws or connections are loose and tighten them as needed.

Step 5: Clean or Replace the Cartridge

The faucet cartridge controls water flow inside the faucet. If it’s clogged with debris or worn out, it may cause leaks.

After removing the handle, look inside the faucet for the cartridge. It’s usually held in place with a retaining clip or nut.
Remove the clip or nut using pliers or a wrench.
Gently pull the cartridge out. If it’s stuck, wiggle it side to side while pulling.
Inspect the cartridge—if it looks dirty or has mineral buildup, soak it in vinegar for about 30 minutes and scrub it with an old toothbrush.
If the cartridge is cracked or damaged, replace it with a new one. Make sure to get the right type for your faucet model.
Once clean (or replaced), put the cartridge back in place and secure it with the clip or nut.

Step 6: Reassemble the Faucet and Test for Leaks

Now that you’ve replaced the O-rings, checked the faucet body, and cleaned or replaced the cartridge, it’s time to put everything back together.

Reattach the spout (if removed) by sliding it back in place.
Put the handle back on and secure it with the screw you removed earlier.
Turn the water supply back on by turning the shutoff valves counterclockwise (or turning the main water supply back on).
Test the faucet by running water and checking for leaks.
If the leak is gone, congratulations! If it’s still leaking, double-check that the O-rings and cartridge are properly installed and that all nuts and screws are tight.

Final Tips for Fixing a Leaky Faucet

If you’re unsure about which replacement parts to buy, take the old O-rings or cartridge with you to a hardware store for a match.
If the faucet still leaks after trying these steps, there might be a deeper issue, and you may need a plumber’s help.
Regularly clean your faucet and check for loose parts to prevent future leaks.

By following these simple steps, you can stop the leak and keep your faucet working like new! 🚰🔧

When to Call a Plumber

Fixing a leaky faucet is usually a simple job, but sometimes the problem is bigger than it seems. If you’ve tried the basic fixes—like replacing O-rings, tightening the faucet, or changing the cartridge—but the leak won’t stop, it might be time to call a plumber.

Here are some signs that you should get professional help:

The faucet is still leaking after repairs. If you’ve replaced the O-rings, cleaned or changed the cartridge, and tightened everything, but water is still pooling at the base, there could be a deeper issue inside the faucet or pipes.
You see water damage under the sink. If the area under your sink is damp, has stains, or smells musty, the leak might be coming from a hidden pipe, not just the faucet. This can lead to mold growth or wood damage if not fixed quickly.
Low water pressure or strange noises. If your faucet is leaking and also has weak water flow or makes gurgling sounds, there could be a blockage or air trapped in the pipes.
You’re unsure how to fix the issue. If taking apart the faucet feels overwhelming or you’re worried about making things worse, it’s okay to call a professional. A plumber can quickly diagnose the problem and prevent further damage.
The leak is coming from the sink connections or water supply lines. If you find water dripping from the pipes under the sink or near the shutoff valves, it’s best to let a plumber handle it.

Why Calling a Plumber Can Save You Money

It might seem like hiring a plumber is expensive, but waiting too long to fix a leak can lead to bigger problems like water damage, mold, and high water bills. A professional can fix the issue correctly the first time, saving you time, stress, and extra costs down the road.

If you’re ever in doubt, it’s better to call a plumber before the problem gets worse! 🚰🔧

Preventing Future Faucet Leaks

Nobody likes dealing with a leaking faucet, so it’s best to take steps to prevent leaks before they happen. Here are some simple ways to keep your faucet in good shape for years to come:

1. Regular Maintenance

Over time, faucet parts like O-rings and cartridges wear out. It’s a good idea to check them once a year to make sure they’re still in good condition. If you notice any cracks, dryness, or stiffness, replace them before they start leaking.

2. Avoid High Water Pressure

If the water pressure in your home is too high, it can wear out the seals inside your faucet faster, leading to leaks. If your faucet drips, hisses, or makes banging noises, your water pressure might be too strong. You can check it with a water pressure gauge, which you can buy at a hardware store. If the pressure is over 60 psi (pounds per square inch), consider installing a pressure regulator to protect your plumbing.

3. Clean Your Faucet Regularly

Mineral buildup from hard water can clog your faucet and damage the internal parts. To prevent this, clean your faucet once in a while using white vinegar:

Fill a plastic bag with vinegar and tie it around the faucet spout.
Let it sit for about 30 minutes, then remove the bag.
Scrub the faucet with a soft brush or sponge to remove any buildup.

This helps keep your faucet working smoothly and prevents leaks caused by blockages.

4. Ensure Proper Installation

If you’re installing a new faucet, make sure it’s done correctly. Follow the instructions that come with the faucet and don’t overtighten screws or nuts, as this can damage seals and lead to leaks. If you’re unsure about installing it yourself, consider asking a friend or hiring a plumber to make sure it’s done right.

Frequently Asked Questions

Here are some common questions people have about fixing a leaking bathroom faucet.

1. How much water does a leaking faucet waste?

Even a small, slow drip can waste a lot of water over time. A leaky faucet can waste up to 3,000 gallons of water per year—that’s about 180 showers’ worth of water! This not only increases your water bill but also wastes an important resource. Fixing the leak as soon as possible can help save money and water.

2. Can I use any O-ring to replace my old one?

No, you need to use the correct size and type of O-ring for your specific faucet model. O-rings come in different sizes and materials, and using the wrong one could cause the leak to continue or even get worse. The best way to find the right replacement is to take the old O-ring with you to a hardware store or check your faucet’s brand and model online.

3. What if my faucet is still under warranty?

If your faucet is still under warranty, you might be able to get free replacement parts or even a new faucet. Check the paperwork that came with your faucet or visit the manufacturer’s website. Many companies offer lifetime warranties on certain parts, especially cartridges and seals, so it’s worth checking before you spend money on repairs.

4. Can I use plumber’s tape to stop a faucet leak?

Plumber’s tape (also called Teflon tape) is great for sealing pipe threads, but it won’t fix a worn-out O-ring or cartridge. If the leak is coming from a threaded connection, plumber’s tape might help. However, if the leak is at the base of the faucet, you’ll likely need to replace the worn-out parts inside.

5. How often should I replace O-rings?

O-rings usually last between 2 to 5 years, depending on how often you use your faucet and the quality of your water. If you have hard water (which has a lot of minerals), O-rings might wear out faster. Checking them once a year and replacing them when they start to look dry, cracked, or loose can help prevent leaks before they start.

6. Is it better to repair or replace my faucet?

If your faucet is fairly new and the leak is caused by a simple issue (like worn-out O-rings or a faulty cartridge), it’s usually cheaper to repair it. However, if your faucet is old, leaking frequently, rusted, or difficult to turn on and off, it might be better to replace it with a new one. A new faucet can improve water efficiency, look better, and save you from dealing with repeated repairs.

Fixing a leaking faucet at the base doesn’t have to be complicated. With the right tools and knowledge, you can stop the leak and prevent future issues. If the problem persists, don’t hesitate to call a plumber.

Why Is My Bathroom Faucet Leaking at the Base? Common Causes and Fixes

How does a Bathroom Faucet work?

Signs That Your Faucet Is Leaking at the Base