Fix a Leaky Double-Handle Bathroom Faucet

A dripping bathroom faucet is one of those tiny problems that somehow feels louder at 2 a.m. The good news is most double-handle faucets leak for fairly boring reasons: a worn seal, mineral buildup, or a bit of debris on a sealing surface. If you can turn off the water and keep track of small screws, you can often fix this in about 30 to 90 minutes, depending on corrosion and how cooperative the parts are.

This guide walks you through disassembling a two-handle bathroom faucet, figuring out whether you have a cartridge or a compression-style stem, and replacing the most common wear items (O-rings, seats, and washers). I will also show you how to avoid the two mistakes I made early on: scratching finished surfaces and overtightening parts until they leak again.

Before you start: find the leak

Double-handle faucets can leak from a few different spots. Pinpointing the leak helps you buy the right parts the first time.

• Drip from the spout (most common): often a worn cartridge, stem washer, seat, or debris on a sealing surface.
• Water around the handle when you turn it: often a worn O-ring or packing, or a bonnet or packing nut that has loosened slightly.
• Water at the base of the spout (if your faucet has a swiveling spout): usually spout O-rings.
• Water under the sink: could be supply connections, the drain, or the faucet mounting nuts.

If you see water under the sink, start there first. A loose supply nut can mimic a “leaky faucet” and send you down the wrong rabbit hole.

Tools and parts

Tools

• Adjustable wrench or a small set of open-end wrenches
• Phillips and flathead screwdrivers
• Allen key set (some handles use a set screw)
• Tongue-and-groove pliers (optional, use gently)
• Small pick or dental tool (helpful for O-rings)
• Clean rag and an old toothbrush
• Silicone plumber’s grease (use what the manufacturer recommends; silicone is a safe default)
• Penetrating oil (optional for stuck parts)
• Painter’s tape (optional for protecting finishes)
• Handle puller (optional, for handles that are truly stuck)

Parts

• Cartridges (cartridge faucets) or stems (compression faucets) for hot and cold, if needed
• O-rings for the stem and/or handle area
• Rubber washers and seats (compression faucets)

Thrifty tip: If you do not know your faucet brand, pull the stem or cartridge first and bring it to the hardware store. Matching by shape is often faster than trying to guess online.

Step 1: shut off water and prep

1. Close the shutoff valves under the sink. Turn them clockwise until they stop.
2. Open the faucet to relieve pressure and confirm water is off.
3. Take a quick photo of the handles and any exposed parts as you go. It helps with orientation later, especially on older faucets.
4. Plug the drain or cover it with a rag. Tiny screws love to jump into drains.
5. Put a towel in the basin to protect porcelain and catch dropped parts.
6. Protect the finish with a little painter’s tape where your tools might bump chrome.

If your shutoff valves do not fully stop the water (it happens), shut off the main water to the house for this repair.

Step 2: remove the handles

Most double-handle faucets hide the handle screw in one of two places:

• Under a small cap on top of the handle (pry gently with a flathead screwdriver)
• On the side of the handle as a set screw (usually Allen key)

1. Remove the cap (if present).
2. Remove the screw or loosen the set screw.
3. Lift the handle straight up. If it is stuck, wiggle gently. Avoid prying hard against the sink or escutcheon.

If the handle is fused in place from mineral buildup, a handle puller is your best friend. It applies even pressure without chewing up the finish.

My early mistake: I once used pliers on a handle without padding and left a neat little tooth mark. Wrap the handle with a rag if you need extra grip.

Step 3: remove trim and expose the valve

Under the handle you may see a decorative sleeve and an escutcheon plate. Some unscrew by hand, others lift off once the handle is removed.

1. Remove any decorative sleeve or cover.
2. Look for what holds the stem or cartridge in place. It is often a retaining nut, and sometimes a small retaining clip on certain brands.
3. Use a wrench to loosen the retaining nut (or remove the clip if your faucet uses one).

If a retaining nut will not budge, apply a small amount of penetrating oil, wait 10 minutes, and try again. Keep the wrench square to avoid rounding the nut. If the whole faucet wants to twist, hold the valve body steady with a second wrench if you can access it.

Step 4: identify the type

Two-handle bathroom faucets are typically one of these:

Compression stem (older style)

• The handle turns several full rotations from off to on.
• Inside is a stem with a rubber washer at the bottom that presses against a seat.

Cartridge stem (common modern style)

• The handle often turns a quarter turn or half turn, but not always.
• Inside is a cartridge assembly with seals or O-rings (some have ceramic discs).

Either way, the fix is similar: remove the stem, replace worn seals, clean sealing surfaces, and reassemble carefully.

Step 5: pull the stem or cartridge

1. With the retaining nut removed (or clip removed), pull the stem or cartridge straight up and out.
2. Set parts on the counter in the order they came off. I like to lay them left to right.
3. Repeat on the other handle if you are rebuilding both sides.

Quick reality check: If one side is leaking from the spout, you can often fix just that side. If the faucet is older, rebuilding both hot and cold at the same time is usually worth it.

Step 6: fix the usual suspects

If it drips from the spout

This is usually caused by a worn sealing surface inside the valve, or grit that keeps it from sealing cleanly.

• Compression stem: Replace the rubber washer on the bottom of the stem. Check the seat inside the valve body. If it is pitted or grooved and your faucet uses a replaceable seat, remove it with a matching seat wrench tool and replace it. Note that some faucets have seats that are not replaceable (they are part of the valve body), and severe damage there may mean replacing the faucet.
• Cartridge style: Replace the cartridge (often the simplest), or replace the seals and O-rings if your brand sells a rebuild kit.

If water leaks around the handle

This is usually an O-ring or packing issue, or a slightly loose nut under the trim.

• If your faucet has a packing nut or bonnet nut, try snugging it gently first. Do not crank it down.
• Locate the O-ring(s) on the stem or cartridge body.
• Remove the old O-ring with a small pick.
• Install the new O-ring and apply a thin film of plumber’s grease that is approved for faucet O-rings (silicone is a safe default).

If it leaks at the spout base (swivel spout)

• Turn off water, then gently lift the spout straight up if it is designed to come off.
• Replace the spout O-rings and grease them lightly.
• Reinstall the spout carefully so you do not nick the new O-rings.

Do not skip cleaning: Mineral buildup can prevent new seals from seating. Scrub the valve opening and parts with an old toothbrush and vinegar if needed, then rinse and wipe dry.

Step 7: reassemble carefully

1. Slide the stem or cartridge back into the valve body in the same orientation it came out.
2. Thread the retaining nut on by hand first to avoid cross-threading.
3. Tighten snugly with a wrench, then stop. Overtightening can crush seals or crack parts.
4. Reinstall trim, sleeves, handles, and handle screws.

My rule of thumb: If you have to white-knuckle the wrench, you are probably past snug. Faucets seal with rubber and precision surfaces, not brute force.

Step 8: turn water on and test

1. Close the faucet handles to the off position.
2. Open the shutoff valves under the sink slowly.
3. Test hot and cold separately, then together.
4. Check for drips at the spout and for seepage around the handles.
5. Look underneath the sink with a dry paper towel and wipe connections to confirm nothing is weeping.

Optional but helpful: If you have an aerator, remove it and run the water for 10 to 20 seconds to flush out any grit you knocked loose during the repair. Then reinstall the aerator.

If you still get a drip from the spout after a rebuild, the most common culprits are a damaged seat (compression), debris caught on the new sealing surface, or the wrong cartridge match (cartridge style).

Troubleshooting

The handle is hard to turn

• You may have overtightened the retaining nut. Back it off slightly.
• Make sure you used an approved grease on O-rings and did not install them twisted.

It leaks only when water is running

• Check for a loose retaining nut or a mis-seated cartridge.
• Inspect O-rings for nicks from installation.
• Make sure the cartridge is fully seated and any retaining clip is properly installed.

It still drips after replacing parts

• Debris can get trapped on a brand-new washer or sealing surface. Disassemble, clean, and try again.
• On compression faucets, a washer that is the wrong thickness can prevent a full seal.
• On cartridge faucets, “almost the same” cartridges often do not seal. Match carefully.

The shutoff valves will not fully stop water

• Use the main shutoff for the repair.
• Consider replacing the shutoff valves later. A working shutoff is one of the best “future you” upgrades.

Buying the right parts

If you know your faucet brand and model, ordering is easy. If you do not, here is the approach that has saved me the most time:

• Bring the old stem or cartridge to the store for a physical match.
• Take a quick photo of the whole faucet and the valve opening on your phone.
• Replace hot and cold with matching parts. Many faucets use mirrored stems that are not interchangeable.
• If parts availability is poor, replacing the entire stem or cartridge assembly is often cheaper than chasing individual washers and seats.

Replace the faucet instead?

I love fixing things instead of tossing them, but there are times a new faucet is the smarter play:

• The valve body is cracked or badly corroded
• You cannot find a matching stem or cartridge anywhere
• The finish is flaking and you are already remodeling the space
• Leaks persist due to severe damage in a seat area that is not replaceable

If you are on the fence, price out the parts first. Many leaks are solved with less than $20 in seals and cartridges.

When to call a pro

• The stem, seat, or retaining nut is seized and you feel like you are about to snap something
• You find cracked supply lines, brittle shutoff valves, or corroded piping that could fail when disturbed
• You cannot access the shutoffs or the faucet mounting hardware safely

Safety and cleanup

• Keep small parts out of reach of kids and pets.
• Do not mix up hot and cold stems as you work.
• Dispose of old parts and wipe up any water under the sink to prevent cabinet swelling.

Once you have done this job once, it is one of those confidence builders you carry into bigger DIY projects. A quiet faucet is a small victory, but it is a satisfying one.