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Plumbing Leaks

Why Is My Faucet Dripping?

A dripping faucet wastes 3,000+ gallons per year. Most fixes cost under $20 and take less than an hour.

Easy Fix

Not urgent, but every drip adds up. Most drips fixed in under an hour.

The Short Answer

Worn Cartridge or Valve Seat. A dripping faucet wastes 3,000+ gallons per year. Most fixes cost under $20 and take less than an hour.

Most Likely Causes (Ranked)

1

Worn Cartridge or Valve Seat

Very Common

Single-handle faucets use a cartridge with seals that harden and crack over years. Water seeps past even when the handle is off.

How to tell: Slow steady drip from spout when off. Extra-tight handle temporarily helps. Faucet 5+ years old.
2

Worn O-Rings

Common

O-rings at the spout base and handle stem dry, flatten, or crack. Water leaks around the base, not from the spout.

How to tell: Water around base when running. Handle feels loose or wobbly.
3

Corroded Valve Seat

Common

Hard water deposits corrode the brass valve seat. New washers can't seal against pitted surfaces.

How to tell: Replaced washer but drip returned quickly. Hard water area. Rough metal inside faucet body.
4

High Water Pressure

Less Common

Pressure above 80 PSI forces water past good seals. Drip may appear only at night when usage drops.

How to tell: Multiple faucets drip. Worse at night. Pipes bang when faucets close. Gauge reads above 80 PSI.
5

Washer Deterioration

Very Common

Older two-handle faucets use rubber washers that wear every 3-5 years. Most common drip cause in older homes.

How to tell: Two-handle faucet. One side drips. Gets worse over time. Must crank harder.

How to Fix It

Replace the Washer

$1-3
  1. 1Turn off supply valves. Remove handle, packing nut, stem.
  2. 2Replace rubber washer at bottom of stem.
  3. 3Match size at hardware store. Reassemble.

Replace the Cartridge

$15-40
  1. 1Note brand/model. Turn off supply.
  2. 2Remove handle, retaining clip, pull old cartridge.
  3. 3Install brand-specific replacement. Reassemble.

Replace O-Rings

$3-8
  1. 1Turn off water. Remove handle and spout.
  2. 2Replace O-rings with plumber's grease on new ones.
  3. 3Reassemble and test.

When to Call a Professional

Supply line leak under sink = potential flood. Check connections.

Sudden drip-to-stream = cracked cartridge. Turn off supply immediately.

Hot-side only = possible water heater pressure issue.

How to Prevent It

Don't crank handles extra-tight.

Replace supply lines every 10 years.

Install water softener for hard water.

Choose ceramic disc cartridges for new faucets.

Frequently Asked Questions

Why drip only at night?

Pressure peaks when usage drops. Above 80 PSI may need a pressure reducing valve.

How much water is wasted?

~3,000 gal/year at 1 drip/sec. That's $20-60/year.

Repair or replace?

Repair if under 10 years and fix costs under $40. Replace if 15+ years or parts discontinued.

Can I fix without turning off water?

No. Turn off supply valves under sink. Exercise these valves yearly so they don't seize.

Related Guides

Pipe Leaking Under Sink
Under-cabinet leaks
Kitchen Faucet Leaking
Kitchen-specific
Shower Head Leaking
Shower drips
Toilet Running
Water waste
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