Direct answer: A faucet that will not shut off usually has one of two problems: the handle is not fully closing the valve inside, or the faucet cartridge is worn, cracked, or jammed with mineral debris. Start by checking whether the handle feels loose or blocked before you assume the cartridge is bad.
Most likely: On most kitchen and bathroom faucets, the most likely cause is a failing faucet cartridge or stem assembly inside the faucet body.
First separate the failure pattern. A faucet that still moves but keeps dripping points one way. A handle that stops short, spins, or feels jammed points another way. Reality check: most faucets that will not shut off are repairable without replacing the whole fixture.
Don’t start with: Do not start by forcing the handle harder or buying a whole new faucet. Forced handles strip parts and turn a simple cartridge job into a bigger repair.
Water keeps flowing, not just dripping, and the handle looks like it is already shut off.
Start here: Start with the handle position and cartridge branch. A stripped handle or failed faucet cartridge is most likely.
The faucet slows down but keeps dripping every few seconds or faster.
Start here: Start with the faucet cartridge or stem sealing surfaces. This is the most common wear pattern.
The handle stops early, feels gritty, or binds before the water shuts off.
Start here: Look for mineral buildup, a loose handle adapter, or a damaged faucet cartridge stem.
Only the hot or cold side keeps running while the other side works normally.
Start here: Focus on that side's faucet stem or cartridge, not the whole faucet.
This is the most common reason a faucet keeps dripping or running after the handle reaches off. The internal seals stop sealing cleanly.
Quick check: Shut the faucet off normally and watch the outlet. If the handle feels normal but water still comes through, the cartridge or stem is the leading suspect.
The handle may look like it is turning the faucet off while the stem underneath is not actually reaching the closed position.
Quick check: Gently wiggle the handle. If it feels sloppy, spins too far, or sits crooked, remove the cap or set screw cover and inspect the handle connection.
Hard-water scale or a small piece of debris can keep the cartridge from seating fully, especially if the problem started suddenly.
Quick check: If the handle feels gritty or the faucet changed behavior all at once after plumbing work or a shutoff event, debris is a strong possibility.
If a new cartridge still does not let the faucet shut off, the sealing surface inside the faucet body may be scored or worn.
Quick check: This moves up the list only after the handle is sound and the correct replacement cartridge does not solve the problem.
You need the faucet safe to work on, and you need to know whether you are chasing a handle problem or an internal sealing problem.
Next move: If the shutoffs hold, you can inspect the faucet without rushing and without flooding the cabinet. If the shutoffs do not stop the water, use the house main water shutoff before taking the faucet apart.
What to conclude: A faucet problem stays manageable when the local shutoffs work. Failed shutoffs do not usually cause the faucet to keep running, but they do change how safely you can proceed.
A loose handle can mimic a bad cartridge. This is one of the easiest ways to avoid buying the wrong part.
Next move: If tightening the handle restores full travel, turn the water back on briefly and test whether the faucet now shuts off normally. If the handle is solid but the faucet still would not shut off before disassembly, move on to the cartridge or stem inspection.
What to conclude: A sloppy handle points to a mechanical connection problem. A solid handle with a faucet that still runs points deeper into the faucet body.
This is the main diagnostic step for a faucet that will not shut off. Most confirmed fixes come from what you find here.
Next move: If you find clear wear or damage, you have a supported repair path: replace that faucet cartridge or faucet stem with a matching part. If the cartridge looks intact but is packed with scale or grit, clean it lightly and the faucet body opening, then reassemble for a test before buying parts.
At this point you should have either a cleaned cartridge worth retesting or a clearly worn part worth replacing.
Next move: If the faucet shuts off cleanly and no new leaks appear, the repair is done. If the faucet still runs from the spout with a solid handle and a correct new cartridge or stem, the faucet body seat or internal casting is likely worn and the faucet is nearing replacement time.
The last step is deciding whether you are done, need one more faucet-specific part, or should stop before damaging the fixture.
A good result: You end with either a confirmed repair or a clean decision that the faucet body itself is worn out.
If not: If you still cannot stop the faucet reliably or the shutoffs will not hold, keep the water off and call a plumber.
What to conclude: Once the handle and cartridge checks are done, repeated guessing usually wastes time and parts. A worn faucet body is not a good place for trial-and-error DIY.
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Most of the time the faucet cartridge or stem is no longer sealing, or the handle is not actually turning the stem to the full off position. A steady stream points more strongly to a cartridge or stem problem than a simple loose handle.
Not for long. Even a fast drip wastes water, and a faucet that suddenly will not shut off can get worse without warning. If the local shutoffs work, use them until you repair the faucet.
Usually it is the cartridge on a single-handle faucet or the stem on one side of a two-handle faucet. Replace the whole faucet only after the handle is sound and a correct replacement cartridge or stem still does not stop the water.
That often points to debris or mineral grit lodged in the faucet cartridge. Remove the cartridge, inspect it, and clean out loose debris before assuming the part is worn out.
No. A spout that now shuts off but leaks at the base is a different leak path. That usually points to seals or wear around the faucet body rather than the shutoff function itself.
No. If only the hot or cold side is failing, start with that side's faucet stem or cartridge. Replace the other side only if it shows the same wear or starts leaking too.