What Causes a Leaky Faucet? How to Diagnose and Fix It
- Feb 19, 2026
- Clint Williams
A leaky faucet is almost always caused by a worn washer, O-ring, or cartridge that no longer forms a watertight seal. In compression faucets, a deteriorated rubber washer lets water drip through the spout. In cartridge, ball, and ceramic disc models, a failed cartridge or cracked ceramic disc is the most common culprit. Hard water buildup and high water pressure can accelerate wear on all faucet types.
A dripping faucet wastes thousands of gallons of water and risks damaging your cabinetry. This guide helps you identify the failed part and complete the repair for compression, cartridge, ball, or ceramic disc models.
This project suits homeowners comfortable with basic hand tools and typically takes 30 to 90 minutes. You will need a wrench, screwdriver, replacement seals or a cartridge, and plumber’s grease. Williams Plumbing & Drain Service has provided code-compliant repairs in Tulsa since 1988. If you encounter heavy mineral buildup or prefer professional faucet repair, our licensed team is available 24/7.
Diagnose the Leak and Identify Your Faucet Type
Pinpointing the leak location before you start saves time and identifies which of the five main components has failed.
Step 1: Track the Water
- Drip from the spout: A steady drip when the faucet is off indicates a failed seal. Compression faucets usually have a worn washer or pitted valve seat; modern units typically have a bad cartridge or ceramic disc.
- Leak at the handle base: Water pooling on the sink deck suggests a worn O-ring or loose packing nut.
- Under the sink: Puddles here usually signal a failed supply line or shut-off valve rather than the faucet itself.
Step 2: Identify Your Faucet Type
- Compression: Features two handles that feel tighter as you turn them off. These rely on rubber washers to stop flow.
- Cartridge, Ball, or Disc: Typically single-handle models. The handle moves smoothly and hits a hard stop without a tightening sensation.
Local Water and Pressure Factors
Hard water in Tulsa frequently leads to valve seat corrosion, which destroys seals faster than normal wear. If leaks occur only at specific times of day, your water pressure may exceed 80 PSI. Once identified, jump to the matching repair path below.
Prepare the Work Area and Shut Off the Water
Locate the hot and cold shut-off valves under the sink before you pick up a wrench.
- Turn both valves clockwise (righty-tighty) until they stop. Use caution with older pipes; do not force a stuck handle.
- Open the faucet handles to drain the water and relieve pressure. If water keeps flowing after a minute, the stop valves have failed.
- Plug the drain with a stopper or rag to prevent losing small screws or clips.
Lay a towel in the basin to catch parts and protect the finish. Photograph the internal assembly before removal to make correct reorientation easier. Gather your tools: a screwdriver, Allen key, adjustable wrench, and needle-nose pliers. Use plumber’s grease for seals and PTFE tape for threaded connections. If replacing a cartridge, bring the old part to the supplier for an exact OEM match.
Plan B: If a shut-off valve leaks or refuses to turn, stop immediately. Williams Plumbing can replace these valves safely to prevent a household flood.
Fix a Worn Washer or O-Ring
A worn washer is one of the most common things that causes a leaky faucet in compression-style fixtures. If a new washer fails quickly, the culprit is likely a pitted valve seat acting like sandpaper on the rubber. Always inspect the metal seat inside the faucet body before finishing.
- Access the stem: Pop the cap, remove the screw, and pull the handle straight up. Use an adjustable wrench to loosen the packing nut, then lift out the stem assembly.
- Replace the seals: Remove the screw at the bottom of the stem to swap the seat washer for an exact size match. If leaking near the handle, replace the O-ring on the stem. Apply a light coat of plumber’s grease to all new rubber parts.
- Inspect the valve seat: Check the metal for pitting or mineral buildup. Tulsa’s hard water often leaves deposits that prevent the washer from seating correctly. Clean the seat with a cloth; if it remains rough, it needs professional resurfacing.
- Reassemble and test: Thread the stem back in and snug the packing nut, but do not over-tighten. Restore the water slowly to confirm the drip is gone and the handle area stays dry.
Replace the Cartridge and Seal O-Rings
Most modern faucet leaks involve a worn cartridge or degraded O-rings. Never force a stuck part with pliers. Twisting can crack the internal plastic or the brass faucet body.
Access and Remove the Cartridge
- Pry off the handle cap and loosen the set screw with a 3/32-inch Allen wrench.
- Remove the handle and pull the U-shaped retaining clip or nut with needle-nose pliers.
- Pull the cartridge straight up. If mineral deposits have seized the part, stop. Use a brand-specific cartridge puller to remove it safely without damaging the valve.
Identify the Fix
- Spout drip: Replace the entire cartridge. Bring the old part to the hardware store to match the stem end and length exactly.
- Base leak: Replace the rubber O-rings on the cartridge body. Apply a thin coat of plumber’s grease to the new rings so they slide in without pinching.
Reassemble and Test
Reinstall the cartridge and handle. Slowly restore the water supply. Verify the spout is dry and no seepage appears at the handle base. If the internal valve seat looks pitted or the new cartridge won’t seat fully, the valve body is likely damaged and needs professional replacement.
Repairing Ball-Type and Ceramic Disc Faucets
CAUTION: Overtightening the adjusting ring or mounting screws will crack internal components. Hand-tighten parts first, then use a wrench for a final quarter turn only.
Identify the Design
Ball-type faucets feature a rounded cap and internal springs. Ceramic disc models contain a plastic or brass cylinder cartridge tucked under the handle.
Ball-Type Repair
These are parts-heavy repairs, so use a complete repair kit.
- Remove the handle and cap, then lift out the ball.
- Pop out the rubber seats and springs with a screwdriver.
- Install new seats and springs from the kit.
- Tighten the adjusting ring until the handle moves smoothly without looseness.
Ceramic Disc Repair
- Remove the handle and unscrew the disc cylinder.
- Replace the neoprene seals on the bottom.
- Clean mineral buildup from cylinder openings and rinse. Tulsa’s hard water makes this step especially important.
- Open the faucet handle before turning the water on slowly to avoid pressure-shocking the ceramic disc.
Verify the Results
Cycle the handle several times. Confirm there is no spout drip and the faucet base remains dry.
When to Call a Professional
Identify Hidden or Slab Leaks: Watch for water stains, mold, or a leaking supply valve under the sink. For Tulsa homeowners, unexplained warm spots on the floor, the constant sound of running water, or a sudden spike in your bill all point to a slab leak. Professional leak detection is required immediately to prevent structural foundation damage and mold growth.
Monitor for High System Pressure: If multiple fixtures leak simultaneously or pipes bang loudly, you likely have high system-wide pressure. This stresses every joint and seal in your home. A plumber must adjust the pressure-reducing valve to prevent pipes from bursting.
Stop for Seized Components: Never force a shutoff valve or a stuck cartridge. Excessive torque can snap the valve or crack the faucet body, resulting in an expensive emergency replacement. If you see deep pitting or corrosion, the fixture needs professional faucet repair to avoid damaging the internal plumbing.
Save time by bundling faucet fixes with other recurring issues like toilet repair or a toilet that flushes on its own. Schedule service with Williams Plumbing for transparent, flat-rate pricing that restores your home’s plumbing in one trip.
Frequently Asked Questions About Faucet Repair
How much does it cost to fix a leaky faucet?
A DIY fix typically costs between $5 and $40 for basic parts like washers, O-rings, or a replacement cartridge. Professional repair costs vary depending on the faucet type and whether your supply lines or shut-off valves also need attention. If a specialized cartridge is expensive or the faucet body shows corrosion, replacing the entire fixture is often more cost-effective than repairing it.
Can a leaky faucet raise my water bill?
Yes. A faucet dripping once per second can waste over 3,000 gallons of water per year. Beyond higher utility costs, constant moisture often leads to mold growth and wood rot in your vanity or kitchen cabinets. Addressing a leak early saves money and prevents expensive property damage.
Can I fix a faucet without shutting off the main water?
Usually. Most homes have local shut-off valves directly under the sink. You can close these to work on the faucet without affecting the rest of the house. If those valves are missing, frozen, or start leaking when turned, you will need to use the main water shut-off or call a professional to replace the faulty valves.
Why does my faucet drip only at night?
Intermittent dripping often signals high water pressure or thermal expansion within the plumbing system. If you notice multiple fixtures dripping at specific times, the issue is likely system-wide rather than a single failed washer. In these cases, professional leak detection is the best way to diagnose the root cause.
About the Author
Clint Williams is the President and owner of Williams Plumbing and Drain—a family-owned company serving the Tulsa community since 1988. With over 35 years of experience, Clint leads his team with a commitment to honesty, integrity, and professional excellence. Dedicated to his local roots, he focuses on providing high-quality residential and commercial solutions paired with the latest plumbing technologies to ensure every customer receives five-star service.