Faucets resource

How to Fix a Leaky Faucet: Causes, Step-by-Step Repair & When to Replace

The four parts behind most drips, cartridge, O-rings, washer or seat and scale, with the tools, a 20-40 minute repair sequence, and when replacement wins.

Brushed-nickel kitchen faucet dripping over an undermount sink, with a cartridge, two O-rings, service cloth, and adjustable wrench on the counter.
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    How to Fix a Leaky Faucet: Causes, Step-by-Step Repair & When to Replace

    Learning how to fix a leaky faucet is one of the highest-payoff repairs a homeowner can do: most drips come from a single worn part that costs a few dollars, and the whole job takes 20–40 minutes with basic tools. The short version — shut off the water under the sink, take the faucet apart, replace the worn cartridge, O-ring, washer or seat, and reassemble. That stops the vast majority of dripping faucets.

    Below we walk through the causes, the exact step-by-step repair for each faucet type, and — just as important — the point where repair stops making sense and you should replace the faucet instead. We make faucets for a living, so we'll be honest about which drips are worth fixing and which ones are telling you the body has reached end of life.

    What causes a leaky faucet?

    Faucet leak-location map linking outlet drips, handle leaks, spout-base leaks, and below-deck water to the first components a maintenance team should inspect.
    Project-generic coordination visual — verify the exact model drawing before release.

    A faucet leaks because one of the parts that holds back pressurized water has worn, hardened, or shifted. The four usual suspects, in rough order of how often they're the culprit:

    • Worn cartridge — the most common cause in modern single-lever faucets. A ceramic-disc or compression cartridge wears or scales up and no longer seals.
    • Cracked or flattened O-rings — small rubber rings that seal the spout and stem. When they harden, you get a drip or a leak around the base of the spout.
    • Worn rubber washer or valve seat — found in older compression (two-handle) faucets. The washer gets compressed and the brass seat corrodes.
    • Mineral scale and debris — hard water deposits hold the seal open. Sometimes a clean is all you need.

    If you're not sure what kind of faucet you have, our guide to the types of faucets walks through cartridge, compression, ball and disc designs so you can identify yours before you open it up. And if you're tripping over the words — tap, spigot, hose bib — the faucet vs spigot glossary sorts the terminology out.

    Which type of leaky faucet do you have?

    The repair depends on what is inside the faucet handle unit, so identify the design before you buy parts. Most home faucets fall into four groups:

    • Cartridge faucet: usually a single handle or two handles, with a cartridge that slides out of the body once the retaining clip or nut is removed. A leaky cartridge faucet is fixed by swapping the cartridge or its O-rings.
    • Ceramic disk faucet: a single lever that sits on a wide cylinder. A leak here usually traces to worn seals or scale on the ceramic disc cartridge, so check the seals before replacing the whole cylinder.
    • Ball faucet: a single lever that moves over a rounded cap. A ball faucet has rubber seats and springs inside the body, and a worn seat or spring is the usual cause of a drip. Repair kits for a ball faucet include these small parts.
    • Compression faucet: two handles that you turn several times to close. Rubber washers press on brass seats, and the washer wears first.

    Is it the hot or cold water that leaks?

    On a two-handle faucet, shut off one supply valve under the sink. If the drip stops, the leak is on that side, and that handle is the one to open first. On a single-handle faucet the cartridge mixes both sides, so you cannot tell by the drip alone.

    Tools and a faucet repair kit: what you need

    You don't need much. A basic faucet repair kit for your faucet's brand/model plus a few hand tools covers nearly every job.

    Item Used for
    Adjustable wrench & slip-joint pliers Loosening packing nuts and supply lines
    Hex (Allen) key set Removing the set screw on single-lever handles
    Phillips & flat screwdrivers Handle screws, prying caps
    Faucet repair kit (cartridge / O-rings / washers / seats) The actual replacement parts — buy to match your model
    Plumber's grease & white vinegar Lubricating new seals; dissolving mineral scale
    Rag & sink stopper or towel Catching water and stopping dropped parts from going down the drain

    How to fix a dripping faucet: step by step

    This sequence works for most single-lever cartridge faucets — by far the most common today. Adjustments for compression faucets follow below.

    1. Shut off the water. Turn the two valves under the sink clockwise until they stop. Open the faucet to release pressure and confirm the water is off. Put a towel over the drain so nothing falls in.
    2. Remove the handle. Pry off the decorative cap, then loosen the set screw with the hex key. Lift the handle straight off.
    3. Pull the cartridge. Unscrew or unclip the retaining nut/clip, then lift the cartridge straight out. Note its orientation — it goes back in the same way.
    4. Inspect and clean. Look for a cracked O-ring, a torn washer, scale buildup, or a scored cartridge. Soak scaled parts in white vinegar for an hour to dissolve deposits.
    5. Replace the worn part. Swap in the matching cartridge or O-rings from your repair kit. Smear a little plumber's grease on new rubber seals so they seat cleanly and last longer.
    6. Reassemble. Reverse the steps — cartridge in the same orientation, retaining clip, handle, set screw, cap.
    7. Turn the water back on slowly and run the faucet. Check under the sink and around the spout base for leaks. A drip that persists after a fresh cartridge usually means a corroded valve seat or a cracked body — see the replace section.

    Before you start: protect the faucet and the parts

    A few small habits keep the repair clean.

    • Shut the water supply valves under the sink. If there are none, close the master supply for the home, then open the faucet to let the water drain out of the line.
    • Wrap masking tape around the jaws of the wrench or pliers so they do not scratch the finish.
    • Use a flathead screwdriver gently when prying off a decorative plastic button or cap. Pry at the edge, not the middle, so the cap is not cracked.
    • Keep small parts in order. Lay each part on a towel in the order it came out. Take a photo at each stage, so you can put the handle back and the inner workings in the right order.
    • Close the drain with a stopper or rag so a dropped screw or washer does not vanish.

    Removing the handle and the cartridge or stem

    Most handle units hide the fixing screw. Pry off the decorative plastic button or the cap, and use a screwdriver or an Allen wrench on the screw beneath. With the handle off, you will see the packing nut on a stem faucet, or the retaining nut or clip on a cartridge faucet. A six sided packing nut is usually turned with an adjustable wrench. Turn it counterclockwise, and lift out the stem or cartridge by hand. Do not force it: if the part sticks, a few drops of white vinegar on the threads beneath can loosen scale.

    Take the old part with you. At the hardware store, hold the old cartridge or washer against the new one and check that it is the same size and shape.

    How to stop a dripping faucet on a two-handle (compression) faucet

    Older two-handle faucets use a rubber washer pressed against a brass seat. To stop the drip: shut off the water, remove the handle and unscrew the packing nut, lift out the stem, and replace the washer at the bottom of the stem. While you're there, check the valve seat with a fingertip — if it feels rough or pitted, dress it with a seat wrench or replace it. Reassemble and test. A new washer on a worn seat will just leak again, so don't skip the seat check.

    New O-rings and washers: getting the seal right

    Replacing O-rings is often all a dripping spout needs. Pull the old plastic O ring off with a small pick, and slide the new one on in the same groove. If the leak is at the spout base, check both the upper and lower rings. On a compression faucet, fit a new washer at the bottom of the stem, and replace its screw if it is rusted. Where the repair kit includes a nylon washer, fit it in the same position as the original.

    Teflon tape on threaded supply connections helps keep them tight, but it does not belong on rubber seals or on the faucet body itself. Use plumber's grease on seals as noted above, and tighten nuts snug by hand and then a little more with the wrench.

    If the leak persists

    If the leak persists after a new part is in, stop and look again before buying more parts. Check these in order:

    1. Is the new cartridge the right part for your model, with the same size and the same orientation?
    2. Is the valve seat rough, pitted or scored? A new washer or seal on a damaged seat will leak again.
    3. Is the water leaking from the handle, the spout base or below the sink? Below the sink points to a supply line or connection, not the faucet.
    4. Is the faucet body cracked, or are the threads beneath the nut stripped?

    If the body is cracked or the threads are stripped, replacing the faucet is the better choice, as described in the next section. Water supply valves that no longer shut off fully are also a reason to call a licensed plumber rather than force the repair.

    When to repair vs. when to replace the faucet

    Repair-versus-replace matrix for maintenance buyers based on leak location, body condition, part availability, repeated service history, and finish condition.
    B2B project-planning visual — confirm the exact model and project documents.

    REPLACEMENT FAUCETS FOR REPAIR-OR-REPLACE DECISIONS

    Replacement faucets — not universal repair parts. Confirm deck drilling, connections, flow, finish, exact cartridge code, and spare-part availability before quote.

    Repair is the right call most of the time. But some leaks are a symptom of a faucet that's done. Here's how we'd decide:

    Sign Repair Replace
    Drip from spout, faucet otherwise solid ✔ New cartridge/washer —
    Leak at spout base ✔ New O-rings —
    Cracked or corroded faucet body — ✔ The leak will return
    Parts no longer available for the model — ✔ Can't source the cartridge
    Loose, wobbly mount or stripped threads Sometimes (re-tighten) ✔ If the base is failing
    Repaired 2–3 times already / 12+ years old — ✔ Better long-term value
    Low flow, heavy internal scaling, finish flaking — ✔ Whole-faucet wear

    If you land on "replace," buy a faucet with a serviceable cartridge and a solid brass or quality stainless body — those are the two things that decide whether you're back under the sink in three years. Our kitchen faucets collection is built around exactly that: replaceable ceramic-disc cartridges and durable bodies that take a real-world repair without you having to throw the whole fixture out.

    Good replacement options if repair no longer pays off

    When a drip means it's time for a new fixture, pick one with parts you can actually replace down the line. A few from our line that are built to be serviced:

    How to make a faucet repair last

    Once you've stopped the leak, a few habits keep it from coming back. Don't crank the handle shut — finger-tight is enough once the seal is good; over-torquing is what chews up washers and cartridges in the first place. Clean the aerator and wipe down the spout every few months to keep scale from creeping into the seals. And in hard-water areas, expect to refresh cartridges or O-rings periodically — that's normal maintenance, not failure.

    Buying kitchen faucets at volume?

    If you manage drips across a property portfolio rather than one sink, the math changes: standardizing on faucets with the same cartridge means your maintenance and MRO team carries one repair kit instead of twenty. As the manufacturer, we supply property managers, multifamily and hospitality builds, facilities programs and private-label buyers directly from the wholesale kitchen faucets collection — consistent cartridges, replaceable seals, finishes matched across a project, and documentation on request.

    For background on sourcing direct, evaluating OEM/ODM partners and finishes, see our faucet manufacturer wholesale supplier guide.

    Frequently Asked Questions

    Why does my faucet keep dripping after I replaced the cartridge?

    Usually because the valve seat or O-rings are also worn, or the new cartridge doesn't exactly match the model. A fresh cartridge on a corroded seat will leak again. Check the seat and seals, and confirm the part number matches your faucet.

    Is it cheaper to repair or replace a leaky faucet?

    Repair is cheaper for a one-off drip — a cartridge or washer kit is a few dollars. Replace when the body is cracked or corroded, parts are no longer available, or you've already repaired it two or three times; at that point a new faucet is the better long-term value.

    Can I fix a leaky faucet without turning off the water?

    No. Always shut the supply valves under the sink (or the main shutoff) before disassembling a faucet. Removing a cartridge under pressure will spray water across the room and risk losing parts.

    How long should a kitchen faucet last before it needs replacing?

    A quality faucet with a solid brass or good stainless body and a serviceable cartridge can last well over a decade, with periodic seal or cartridge refreshes. Lifespan depends on water hardness, build quality and how it's used.

    What is your MOQ and lead time for wholesale kitchen faucets?

    You can order a single unit to evaluate. Wholesale project pricing starts from a per-model minimum (our standard MOQ is 50 pcs per model), with final MOQ depending on model, finish and customization, confirmed on your quote. Samples ship in days; a standard production run takes a few weeks once the spec is locked, with container and custom orders longer plus ocean transit — exact timing per PO.

    Do you offer OEM finishes and certification documents?

    Yes. We do OEM/ODM with custom finishes and private-label branding, and we provide material certificates, drawings and cut sheets on request. Certifications such as cUPC are confirmed per model and destination market rather than as a blanket claim.

    Sourcing at volume? If you buy for a property portfolio, hotel, multifamily build, facilities/MRO program, or a private-label line, send your target product, quantity and destination port and a SANIKB engineer will return a quote with MOQ, lead time and a full documentation pack. Request a quote.

    — Rokan

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