Sink Faucet Dripping
A dripping sink faucet isn't just annoying — a single drip per second wastes over 3,000 gallons of water per year. The good news: in the vast majority of cases, a worn cartridge, damaged O-ring, or corroded valve seat is the cause, and any of those repairs costs $10–$25 in parts and takes less than an hour. This guide walks through identifying your faucet type, shutting off supply safely, removing the handle and internal mechanism, replacing the worn parts, and reassembling without leaks.
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Common Symptoms
- Faucet drips from the spout even when fully turned off
- Drip worsens after extended hot or cold use
- Handle requires more force to stop the drip over time
- Water stain or mineral ring in the sink basin below the spout
- Visible water drip rate has increased over recent weeks
Most Likely Causes
- 1
Worn Cartridge (Most Common in Single-Handle Faucets)
A cartridge is a self-contained valve unit inside the faucet body that controls water flow and temperature. As the cartridge seal wears, it can no longer form a watertight seal when closed, resulting in a continuous drip. Cartridge replacement is the most common faucet repair — the part is brand-specific ($10–$40) and installs in minutes.
- 2
Damaged O-Rings
O-rings are rubber sealing rings that sit on the faucet stem and cartridge body. They degrade with age, heat cycles, and mineral exposure. Worn O-rings allow water to bypass the seal, causing dripping from the spout or leaking at the handle base. An O-ring assortment kit covers all common sizes for $5–$10.
- 3
Corroded Valve Seat
The valve seat is the connection point between the faucet and the spout. Mineral deposits (sediment and limescale) accumulate on the seat, creating a rough surface that prevents the washer or cartridge from sealing cleanly. If replacing the cartridge or washer doesn't stop the drip, inspect and resurface the valve seat with a seat wrench and seat grinder ($15 rental).
- 4
Loose or Worn Packing Nut
On compression-style faucets (older two-handle designs), the packing nut holds the stem assembly in place. Over time the packing material (graphite or rubber rope packing) degrades and the nut loosens, allowing water to seep past the stem. Tightening the nut 1/4 turn or replacing the packing fixes this without replacing the entire stem.
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Quick DIY Checks
Always shut off both hot and cold supply valves fully before disassembling a faucet. Skipping this step — even briefly — can result in a full-pressure water surge soaking the cabinet, walls, and floor. Confirm the valves are closed by turning on the faucet and waiting for all flow to stop before proceeding.
Label the hot and cold supply shutoff valves before closing them — it is easy to confuse them under a sink, especially in dim lighting. Accidentally restoring the wrong valve first during reassembly can send hot or cold water back into a partially assembled faucet and spray water inside the cabinet.
- 1Step 1 — Shut off supply valves under the sink: locate the hot and cold supply valves on the supply lines directly under the sink. Turn each valve clockwise until it stops — a quarter-turn ball valve will be perpendicular to the supply line when closed; a multi-turn compression valve requires several full rotations. Label each valve with tape (hot left, cold right) to avoid confusion during reassembly. Confirm the valves are fully closed before touching the faucet.
- 2Step 2 — Turn on the faucet to release residual pressure: open the faucet handle(s) fully to both hot and cold positions. Allow any trapped water in the supply lines above the valves to drain out through the spout — this relieves pressure and prevents a surprise water surge when you disassemble the handle. Place a towel in the basin to catch drips.
- 3Step 3 — Remove the handle (decorative cap conceals set screw on most faucets): look for a decorative cap on top of the handle — it is usually a plastic or metal disc labeled H/C or with a brand logo. Pry it off gently with a flathead screwdriver wrapped in tape to protect the finish. Underneath you will find a Phillips or hex (Allen) set screw. Remove that screw and lift the handle straight up off the stem. If it's stuck, wiggle it gently — do not force it. On older two-handle faucets, a packing nut may be exposed after handle removal.
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Repair vs Replace
A dripping faucet is almost always worth repairing rather than replacing. Even a brand-name cartridge replacement ($25–$40) is far cheaper than a new faucet plus installation. Only consider full faucet replacement if the faucet body is cracked, if the valve seat is damaged beyond resurfacing, or if the faucet is over 20 years old and parts are no longer available. Modern cartridge faucets are designed for DIY cartridge swaps without specialized tools.
Est. Repair Cost
$10–$60 (cartridge $10–$40; O-ring kit $5–$10; basin wrench if needed $15–$25)
Est. Replacement Cost
$150–$400 for a new faucet installed by a plumber
Recommended Tools & Parts
- Buy on Amazon →
Moen 1225 Cartridge Replacement
OEM replacement cartridge for Moen single-handle faucets. The 1225 fits the majority of Moen kitchen and bathroom faucets built since the 1990s (check your model — some require the 1222 or 1200). Includes cartridge and O-rings. Drop-in replacement; no tools beyond the retaining clip removal. Moen backs this with a lifetime warranty when purchased through authorized channels.
$15–$30
- Buy on Amazon →
Danco O-Ring Assortment Kit
Complete O-ring assortment covering all standard plumbing sizes for faucet stems, cartridges, and supply valve connections. Includes sizes 1 through 11 (most common residential faucet sizes). Made from BUNA-N rubber rated for hot and cold water service. Use with silicone plumber's grease for best seal and long life.
$8–$15
- Buy on Amazon →
Ridgid Adjustable Basin Wrench
Spring-loaded jaw basin wrench for reaching supply line nuts in the confined space behind the sink basin. The swiveling jaw reaches fasteners in spaces where a standard wrench won't fit. Essential for removing and tightening the faucet mounting nut under a deep sink. Adjustable jaw fits 3/8-inch to 1-1/4-inch supply line nuts.
$20–$35
Links are Amazon affiliate links (tag: fixitfastai-20). Prices are estimates.
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Related Repair Guides
This section combines editorial `relatedSlugs` from the article source with metadata-based matches so each guide links deeper into the repair library.
Dripping Faucet Repair — Ball, Cartridge, Ceramic Disc & Compression Fix Guide
A faucet dripping once per second wastes ~3,000 gallons/year and adds $15–25 to your water bill. Covers all four faucet types — compression, ball, cartridge, and ceramic disc — with exact part numbers and step-by-step procedures.
Read guide →Outdoor Faucet Not Working: Hose Bib Repair Guide
Outdoor faucet with no water, low pressure, or a drip from the stem? This guide covers freeze damage inspection, packing nut and washer replacement, vacuum breaker failure, and when to replace the whole hose bib.
Read guide →Outdoor Faucet Leaking
Outdoor faucet dripping or leaking at the handle? A worn packing washer or O-ring is almost always the cause — a $10 fix that takes less than an hour.
Read guide →Shower Faucet Dripping — Fix a Leaky Shower Valve Without Calling a Plumber
Shower faucet dripping even when off? A worn cartridge or valve seat is almost always the culprit — a $15–$40 part and 45–90 minutes stops the drip for good.
Read guide →Hose Bib Leaking
Hose bib dripping from the spout or leaking around the handle? Tighten the packing nut or swap the washer — most repairs take under 30 minutes.
Read guide →Toilet Flapper Replacement
Toilet running constantly or randomly refilling? A worn flapper is the #1 cause — replace it in 30 minutes for under $15.
Read guide →Keep Exploring
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Frequently Asked Questions
- How do I identify what type of faucet I have?
- The four common residential faucet types are: (1) Compression — two handles, you feel resistance as you tighten them to stop flow; common in homes built before 1980. (2) Ball — single handle that rotates and tilts; common in Delta kitchen faucets; a loose ball or worn seats/springs cause drips. (3) Cartridge — single or two handles; the handle pulls up/down to control flow; cartridge pops straight out for replacement; used by Moen, Price Pfister, and many others. (4) Ceramic disc — single lever on a wide cylindrical body; very durable; rarely drips unless the disc is cracked or contaminated. Identifying the type determines which repair parts to buy.
- Why does my faucet only drip when the hot water is on?
- A drip that occurs only on the hot side means the hot-side cartridge or O-ring is worn but the cold-side is still sealing properly. Hot water accelerates rubber degradation, so the hot-side cartridge typically wears out first. Replace only the hot-side cartridge or stem washer — you don't need to touch the cold side unless it's also dripping.
- Can I replace just the O-ring instead of the whole cartridge?
- Yes — if the cartridge body itself is in good condition (no cracks, no scoring on the sealing surfaces), replacing just the O-rings on the cartridge or stem costs $5 or less and resolves the drip. However, if the cartridge has been leaking for months, the internal sealing surfaces may be damaged and an O-ring replacement alone won't last. When in doubt, replace the full cartridge — the parts cost difference is usually under $20.
- When should I replace the whole faucet instead of repairing it?
- Replace rather than repair when: the faucet body is cracked or corroded through; replacement cartridges are discontinued (very old or obscure brands); the valve seat is damaged beyond resurfacing; or the faucet is over 20 years old with multiple simultaneous issues. Also consider upgrading if you're doing a bathroom or kitchen renovation — it's much easier to install a new faucet when the supply lines are already disconnected.