Bathroom Faucet Leaks At Base When Turned On: How To Fix It

Leaky faucets quickly become a nuisance, and while some are easy to spot, others run under the radar. Leaks around the base are one of the types that often go undetected for a while since it’s an area where water splashes commonly end up. However, once you notice the leak, it usually becomes painfully apparent.

Key Points:

  • Leaky faucets can go unnoticed until they start affecting water bills and performance.
  • Common culprits of a bathroom faucet leaking at the base are faulty O-rings or cartridges.
  • DIYers can tackle this problem by turning off the water supply, draining the lines, and replacing worn-out O-rings with new ones.

So, maybe you noticed your water bill is higher than noticeable, so begin looking for the culprit. The toilets aren’t running, and there aren’t any apparent leaks, save for this one faucet. And it appears to be leaking from the base. Now what? Before you call a plumber, read through this guide – sometimes, the fix is easier than you think.

How Can I Tell If My Bathroom Sink Faucet Is Leaking From The Base?

Since you ended up on this article, we’re guessing you’ve confirmed the leak is coming from your faucet’s base. But, just in case, let’s review how to double-check. Leaks around the bottom of the tap can go unnoticed for a while, especially because we often splash water on this area as we wash our hands or go about other tasks.

So, in many cases, we might not notice the water leak until it starts to cause problems. To confirm the water leak stems from the base of the faucet, start by drying the faucet. Dry the entire faucet body, handles, and around the bottom. Then, turn the water on and watch for leaks underneath the faucet.

If you notice water pooling around the base of the faucet, ensure it isn’t coming from somewhere else. Sometimes, leaks from the faucet handle will give the impression of leaks from the bottom of the tap. So, look at the front and back of the faucet handles to ensure water isn’t trickling down from there.

Why Is My Bathroom Faucet Leaking At The Base?

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When a faucet springs a leak and water begins pooling around the base of the tap, there’s usually one of two culprits behind the issue. Here are the most common causes of water pooling around the base of a bathroom faucet:

Faulty O-Ring

In most bathroom faucets, there are O-rings to create tight seals where waterproofing is necessary. These O-rings are often made of rubber, which can dry up and crack after a while. When the O-ring cracks, water may seep down the faucet body while running, allowing it to escape out the bottom.

This causes pooling around the base of the faucet, leading to that ever-growing puddle.


Although this culprit is rarely the cause, we’ve seen it happen. Sometimes, the cartridge within the faucet wears out, allowing water to slip through when it shouldn’t. In many cases, this accompanies other worn-out components, like tired O-rings, so water can slip through and puddle around the base of the faucet.

How Do I Stop My Faucet From Leaking From The Base?

If your faucet is leaking from the base, you might be able to correct the fix yourself. Before you start moving through either set of steps, be sure to turn off the water to the faucet. Most bathroom faucets feature shut-off valves on the supply lines beneath the sink, so turn both sides off by turning clockwise.

Or, if your faucet doesn’t have isolated supply lines, you might need to turn the water off at the main water shut-off valve. Once you turn the water supply off, drain the water from the lines by running the faucet until water no longer comes out of the spout. After that, you’re ready to start the project!

Replace The O-Rings

If you suspect the O-rings might be the problem, here’s what you’ll need to tackle the project:

  • Replacement O-rings
  • Adjustable pliers or a wrench
  • Screwdriver set
  • Towel

Once you gather the necessary materials, follow these instructions:

  1. Cover the sink drain with a towel to ensure you don’t lose any parts.
  2. Remove the faucet handle cap, if applicable, using a flathead screwdriver or your fingernail. Be careful not to damage the finish.
  3. Unthread the screw from the handle using a Philips screwdriver. Sometimes, there might be a hex screw, so you may need an Allen key to remove it.
  4. Remove the handle and set it aside.
  5. Once you remove the screw, loosen the valve from the faucet body with pliers or a wrench. Simply secure the pliers/wrench around the base of the valve, then rotate in a counterclockwise direction.
  6. Remove the valve by lifting it away from the base.
  7. With the valve out of the faucet, examine it for O-rings. Check for wear and tear, then remove and replace old ones as necessary.
  8. Reassemble the faucet, ensuring you align tabs or grooves as needed for a snug fit. Tighten the valve, then reattach the handle and secure it with the set screw. Replace the handle cap.
  9. Last, you need to check your handiwork. Turn the water back on, then check for leaks. If the leaks persist, turn the water back off and move to the following method.

Replace The Cartridge

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Sometimes, the problem may be with the faucet’s inner cartridge. This piece controls the flow of water through the faucet, so you’ll probably notice leaks when it goes on strike. If you have a two-handle faucet, you may need to replace the cartridge on both sides. Of course, if the leak only comes from one side, you won’t need to replace both.

Here’s what you’ll need:

  • Allen wrench
  • Philips and flathead screwdrivers
  • Pipe wrench or tongue-and-groove pliers
  • Plumber’s grease
  • Replacement cartridges
  • towel

Once you gather your materials, follow these steps to replace the cartridge:

  1. First, make sure you turn the water back off (if you tried replacing the O-rings). Drain water from the lines, then cover the drain with a towel.
  2. Remove the faucet handle by removing the decorative cap and unthreading the screw. Pull the handle straight up to remove it from the faucet.
  3. On the top of the cartridge, you should see a retaining nut. Using a pipe wrench or tongue-and-groove pliers, remove the nut and set it aside for later.
  4. Take note of the cartridge’s orientation, then pull the old cartridge out of the faucet body using pliers (tongue-and-groove or needle-nose pliers will work). You’ll need to know how to insert the new cartridge, so if you need to, take a picture of the old cartridge in the faucet body to ensure you remember the proper orientation.
  5. Use your finger to coat a small amount of plumber’s grease on the new cartridge’s O-rings. Insert it into the faucet body and ensure it’s oriented correctly.
  6. Retrace your steps to reassemble the faucet – replace the retaining nut, tighten it, reattach the handle and secure it, and then replace the decorative cap.
  7. Turn the water back on and check your faucet for leaks. Be sure there’s no standing water around the faucet before checking for leaks.

Replace The Faucet

Bathroom Faucet

Unfortunately, there are some scenarios where replacing the faucet altogether is your best bet. This is usually true for faucets that have been around for several decades, as most bathroom faucets tap out after 15 to 20 years.

So, if you’ve tried replacing the O-rings and cartridge, but the problem still persists, you might want to consider investing in a new faucet. Replacing the tap can be pricey, but it’s usually worthwhile if the old faucet continually requires repairs. You can find bathroom faucets for less than $100, so you don’t necessarily have to splurge with a several-hundred-dollar faucet to replace the old one.

Hire A Plumber

If your faucet is still relatively new and in good condition, but nothing you do seems to fix the problem, you might want to hire a plumber. They should be able to catch what you’re missing and over advice on the best course of action. Most plumbers charge between $45 to $150 per hour, although this might change based on the difficulty of the repair.

Frequently Asked Questions (FAQs)

Can I Get A Free Replacement Cartridge For My Faucet?

You might have heard rumors of free cartridge replacements for faucets. While this can be true, it doesn’t always apply. Most major brands, like Kohler, Delta, and Moen, offer excellent warranties that cover leaks and drips. Since the cartridge is a common culprit behind this issue, they will usually replace it for free.

However, there are usually specific requirements you need to meet to receive a free replacement cartridge for your faucet. That said, it doesn’t hurt to contact the faucet brand’s customer support team for warranty help. Who knows, you might get a free cartridge replacement out of the deal!

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