A dripping or leaking bathroom faucet wastes water, raises your utility bill, and can lead to stains and mold if ignored. Many common faucet problems—drips, low flow, or a loose handle—are caused by worn seals, cartridges, or clogged aerators and can be fixed by a homeowner with basic tools. This guide walks you through diagnosing the issue, shutting off water safely, disassembling the faucet, replacing worn parts, and testing the repair. You’ll learn how to identify cartridge vs. compression faucets, when to replace parts, and preventative maintenance tips so the faucet stays problem-free. Safety tips and a clear “when to call a professional” section help you choose the right course of action.

Key Takeaways

Identify the faucet type (cartridge, ball, ceramic disk, compression) before buying parts.
Always shut off water and relieve pressure before disassembly.
Most leaks are caused by worn cartridges, O-rings, or seats and can be replaced.
Use the right replacement parts and plumber's grease for a durable seal.
Call a pro for complex valve replacements, persistent leaks, or plumbing access issues.

Tools Needed

Adjustable wrench
Screwdriver set (flathead and Phillips)
Allen wrench (hex key) set
Pliers (needle-nose and slip-joint)
Basin wrench (if supply line nuts are hard to reach)
Flashlight
Bucket and towels
Cleaning brush or old toothbrush

Materials Needed

Replacement cartridge, valve stem, or O-ring kit (matched to faucet brand/model)
Plumber’s grease (silicone-based)
Plumber’s tape (Teflon tape)
Replacement aerator (if needed)
Rags or shop towels
Small container to hold screws and parts

⚠️ Safety Warnings

Always turn off both hot and cold shut-off valves before starting work to avoid flooding.
Relieve pressure by opening the faucet after shut-off; watch for hot water to avoid burns.
If you smell gas or suspect major sewer or water line damage, evacuate and call professionals immediately.
Wear eye protection when working under the sink to prevent debris from falling into your eyes.
If soldering, working on galvanized or lead pipes, or uncertain about local codes, hire a licensed plumber.

Step-by-Step Instructions

Step 1: Diagnose the Problem and Identify Faucet Type

Start by observing the symptom: a steady drip from the spout, leaks around the handle base, low flow, or a loose handle. Turn the faucet on and off to reproduce the issue. Next, identify the faucet type—compression (separate hot and cold handles), cartridge (single or double handles with a cartridge), ball (rounded body, single handle), or ceramic-disk (flat, single-handle assembly). Look under the sink for a brand label or take a clear photo of the faucet and any stamps for parts lookup. Knowing the type ensures you order correct replacement parts; mismatched parts won’t fit and can worsen leaks.

💡 Tip: If you can’t find a brand, take the old cartridge or stem to a hardware store for comparison.

⚠️ Do not force parts to remove—this can break components and complicate the repair.

Step 2: Shut Off Water and Prepare the Workspace

Locate the shut-off valves under the sink and turn both hot and cold clockwise until snug. If valves are seized, shut off the house’s main water supply. Put a bucket under the supply lines to catch residual water. Open the faucet to drain remaining water and relieve pressure. Lay down towels to protect the cabinet and counter from water and dropped parts. Clear the area of toiletries and remove any items in the cabinet to give yourself room. Proper prep prevents water damage and keeps small screws and springs from getting lost during disassembly.

💡 Tip: If you’re unsure which valve controls the faucet, turn them one at a time and test the faucet while someone watches the shut-off.

⚠️ Be cautious of hot water when draining; let hot water cool before opening the faucet if needed.

Step 3: Remove Faucet Handle(s) and Access Internal Parts

Cover the drain with a towel or use a sink stopper and then remove the faucet handle(s). Look for a small decorative cap on top of the handle; pry it off with a flathead screwdriver to reveal a set screw, or check the back or side for an Allen screw. Remove screws and lift the handle straight up; you may need gentle wiggling. Once handles are off, remove any escutcheon plates or retaining nuts using an adjustable wrench or pliers. Keep screws and small parts in your container. With the handle removed you’ll see the cartridge, stem, or ball assembly—this is what you’ll inspect and likely replace.

💡 Tip: Take photos at each stage so you can reassemble parts in the correct order.

⚠️ Avoid using excessive force on trim pieces—plastic caps and chrome plating can chip or crack.

Step 4: Inspect and Remove the Cartridge, Stem, or Ball

Examine the exposed internal parts for corrosion, mineral buildup, or damaged seals. For cartridge faucets, remove the retaining clip and pull the cartridge straight up. For compression faucets, unscrew the packing nut and remove the valve stem. For ball faucets, note the ball position and remove cam and packing. Clean the housing with vinegar or a descaling solution if mineral deposits are present. Compare the removed part to the replacement to confirm a match. If the mechanism is corroded or pieces are visibly worn or cracked, replace the entire cartridge or stem rather than attempting patch repairs.

💡 Tip: If parts are stuck, soak with a little penetrating oil and gently work them free—avoid hammering.

⚠️ Do not mix up hot and cold parts; reassembly with swapped sides can cause improper operation.

Step 5: Replace Seals, O-Rings, or the Entire Cartridge

Install new O-rings, seals, or the factory replacement cartridge according to the manufacturer’s instructions. Lightly coat O-rings and seals with plumber’s grease to ensure smooth seating and longer life—do not use petroleum-based grease on rubber. Insert the new cartridge or stem carefully, aligning tabs or notches with the housing. Reinstall retaining clips, nuts, and packing in the original order. If replacing multiple components, take your time to seat each piece correctly to avoid cross-threading or pinched seals which cause leaks. Using exact replacement parts is critical—universal kits may work but can be less reliable.

💡 Tip: Bring the old part to the store if buying replacements in person to ensure a perfect fit.

⚠️ Avoid using excessive grease inside the waterway; use only a light film on O-rings.

Step 6: Reassemble the Faucet and Restore Water Supply

Reinstall escutcheon plates and handle(s) in reverse order of removal. Tighten screws snugly but avoid overtightening decorative screws or plastic components. Reattach supply lines if you disconnected them, wrapping male threads with Teflon tape where appropriate. Slowly open the shut-off valves to restore water and watch for leaks at connections. Operate the faucet to seat the new cartridge and to flush any debris. If you see drips at fittings, turn off water again and tighten the leaking connection; avoid using pipe dope on compression fittings unless recommended by the manufacturer.

💡 Tip: Open valves slowly to catch leaks early and prevent sudden pressure surges.

⚠️ If a connection leaks after tightening, do not force it—recheck thread type and gasket placement.

Step 7: Clear Aerator or Mineral Buildup for Low Flow Issues

If problem is low flow rather than a leak, remove and inspect the aerator at the spout tip. Unscrew the aerator with pliers wrapped in tape to protect the finish. Clean screens and remove mineral deposits with vinegar or a descaling solution; scrub with a toothbrush. If threads are corroded or the aerator is damaged, replace it. After cleaning or replacing, reinstall the aerator and test flow. If flow is still poor, check supply valves under sink to ensure they're fully open and inspect supply line filters or shut-off screens. Persistent low flow may indicate a blockage in the supply lines or a failing cartridge.

💡 Tip: Keep a spare aerator in your toolbox—replacement is inexpensive and quick.

⚠️ Beware of hard scrubbing on chrome finishes; use plastic tools or cloth to avoid scratching.

Step 8: Final Tests, Cleanup, and Preventive Maintenance

Run the faucet through hot and cold cycles and check all joints, under-sink fittings, and the spout for leaks for at least 10-15 minutes. Check operation of the handle and smoothness of movement. Clean the faucet surface and reinstall any accessories. Dispose of old rubber parts and wiped-off mineral residue. For ongoing prevention, periodically clean the aerator, gently tighten handle screws if they loosen, and inspect under-sink connections every six months. Consider replacing inlet supply lines every 5–10 years or sooner if they show wear to prevent sudden failures.

💡 Tip: Keep a small maintenance log with the date and parts replaced to track component life.

⚠️ If you notice any seepage after 24 hours, retighten connections or re-check seals; persistent seepage requires professional inspection.

When to Call a Professional

Call a professional plumber if you encounter seized or corroded valves that won’t budge, persistent leaks after replacing cartridges and seals, or if you need to access or replace shut-off valves or supply lines located in tight or obstructed spaces. Complex faucet systems (multi-hole roman tubs, wall-mounted faucets, or integrated temperature control systems) often require specialized tools and expertise. Also call a pro if you discover water damage, mold, or structural rot under the sink, or if repairs require soldering, cutting supply lines, or working on the home’s main water feed. Licensed plumbers can ensure code-compliant repairs, provide warranty-backed labor, and prevent costly mistakes like cross-threaded fittings or improper seals.

Frequently Asked Questions

How do I know which replacement part I need for my faucet?

Identify the faucet brand and model first—check under the sink, the faucet body, or your original purchase paperwork. If uncertain, remove the cartridge or stem and bring it to a hardware store or match it online using photos and dimensions. Many manufacturers list part numbers on their websites. If your faucet is older or obscure, universal repair kits may work, but exact-match parts ensure the best fit and longest life.

Can I fix a leaking faucet without shutting off the house water?

You should always shut off the local shut-off valves for that sink before disassembling the faucet. If the shut-off valves are faulty, you may need to shut off the main water supply. Working with the water on risks flooding and makes replacement much harder—always relieve pressure and confirm no water flow before removing internal parts.

Why is my faucet still dripping after I replaced the cartridge?

If dripping continues, check that the replacement cartridge is the exact model and installed with correct orientation. Inspect the valve seat for grooves or corrosion—damaged seats can keep a faucet from sealing even with a new cartridge. Also confirm O-rings and seals were installed correctly and that retaining clips and packing nuts are properly tightened. If issues persist, the valve housing may be damaged and require professional repair or replacement.

How often should I perform maintenance on bathroom faucets?

Perform light maintenance every 6–12 months: clean aerators, check for loose handle screws, and look under the sink for drips. Replace O-rings and seals every 3–5 years or sooner in hard-water areas. Regular checks help catch small leaks before they cause bigger damage and extend the life of your faucet components.

How To Bathroom Faucet Repair