Kitchen Faucet Leaking at the Base? The 15-Minute O-Ring Swap
Water at the base usually means worn O-rings where the spout swivels. Shut off the water, swap the rings, and the leak stops.
By Jamilur Rahman Updated November 5, 2026 · 6 min read
- Time
- 15-30 min
- Cost
- Under $20
- Difficulty
- Medium
In this guide
Quick answer
A leak at the base of a kitchen faucet usually comes from worn rubber O-rings where the spout swivels on the faucet body. Turn off the water, lift off the spout, replace the rings with a matching set and coat them with plumber's silicone grease. If water pools even when the faucet is off, check the mounting nut and supply lines instead.
Free fix vs. permanent fix
Dry it, find the source and snug it up
- Dry the faucet and deck, then run water to see where it appears
- Tighten the set screw or cap under the handle a little
- Check under the sink for wet supply lines and a loose mounting nut
- Wipe mineral crust off the base
How long it lasts: A few days to a few weeks. Tightening a loose cap or screw can slow a leak, but the rubber is still worn.
A new spout O-ring set, with silicone grease
O-rings are the seal between the swivel spout and the faucet body. They harden, flatten and crack with age, so water creeps past them. New rings restore the seal, and a thin coat of grease protects them.
What to get: Faucet spout O-ring kit
How long it lasts: Years. The rubber is fresh, and the grease keeps it from drying and cracking.
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What you'll need
-
Hex key set
Fits the small set screw under the handle or spout cap
You have it -
Towel and small bowl
To catch drips and hold small parts
You have it - Illustration
Plumber's silicone grease
A thin coat on each new ring
- Our pick Illustration
Faucet spout O-ring kit
Match it to your faucet brand and model
- Illustration
Faucet O-ring assortment
Only if you can measure your old rings
- Illustration
Replacement faucet cartridge
Only if the handle leaks or the spout drips
Why it happens
Worn spout O-rings
Two rubber rings sit in grooves at the base of a swivel spout. They dry, flatten and crack over the years, and hard water speeds it up. Water seeps out each time the faucet runs, especially as you swing the spout.
A loose cap or set screw
On many single-handle faucets, a cap or screw holds the assembly down. If it works loose, parts shift and the seals leak.
A loose mounting nut or worn deck gasket
A faucet that rocks or sits crooked can let water under the base and onto the counter. That is a different leak, and new O-rings will not fix it.
Mineral crust and age
Scale builds on the spout shaft and chews at the rings. On an old faucet, parts can be worn past a simple swap.
Try this first (free)
Do these in order, starting with the simplest.
-
Find the exact source
Tool used: Towel and small bowlDry the faucet and counter. Turn the water on and watch. A leak only while water runs, worse when the spout moves, points to the O-rings. Water on the counter with the faucet off points to the mounting nut or a supply line.
-
Snug the cap or set screw
Tool used: Hex key setLook for a small screw or cap near the base or under the handle. Tighten it a quarter turn with a hex key. Do not over-tighten.
-
Shut off the water
Close both shutoff valves under the sink (clockwise), then open the faucet to release the pressure. Plug the drain or lay a towel in the sink to catch small parts.
-
Take off the spout and photograph the rings
Tool used: Hex key setRemove the handle and cap as your faucet allows, then lift the spout straight up, twisting gently. Take a photo of the rings before you remove them, so you can put them back the same way.
-
Match the new rings
Tool used: Faucet spout O-ring kitPull off the old rings with a small pick or your fingernail. Compare each one with the new set, size by size, and fit the new ones in the same grooves.
IllustrationCheck price on AmazonTool for this step
Faucet spout O-ring kit · Match it to your faucet brand and model
-
Grease, reassemble and test
Tool used: Plumber's silicone greaseWipe the grooves clean and rub a thin coat of silicone grease on the new rings. Do not use petroleum jelly, which can swell and soften some rubber. Reassemble, open the shutoffs slowly, swing the spout and check under the sink.
IllustrationCheck price on AmazonTool for this step
Plumber's silicone grease · A thin coat on each new ring
When free fixes aren't enough
Tightening a screw rarely lasts, because the rings themselves have gone hard. A new set rebuilds the seal. If fresh rings still leak, or water seeps from the handle or the spout tip, the cartridge is the part to replace. Stop and call a plumber if the faucet body is cracked, the shutoff valves will not close, or the supply lines are corroded. A leak under the sink you cannot trace also needs a pro.
Buy the fix
Still stuck after the free fixes? These are the products we would look at.
| Pick | Product | Fixes | Who it's for | Buy |
|---|---|---|---|---|
| Best pick | Faucet spout O-ring kit | water seeping from the swivel base of the spout | Anyone whose leak shows only while water runs and the spout moves. | Check price |
| Budget pick | Faucet O-ring assortment | the same leak, if you can match the old ring | Someone comfortable measuring the old rings. | Check price |
| Upgrade pick | Replacement faucet cartridge for your model | handle leaks and drips from the spout tip | Water leaks at the handle, or the spout still drips after new rings. | Check price |
Faucet spout O-ring kit
Fixes: water seeping from the swivel base of the spout
Look for: Made for your faucet's brand and model, or sized by measurement; Rubber rated for hot and cold water; Every ring your spout uses, in the right sizes.
- Who it's for
- Anyone whose leak shows only while water runs and the spout moves.
- Honest downside
- Water collects on the counter with the faucet off. Check the mounting nut and supply lines first.
Faucet O-ring assortment
Fixes: the same leak, if you can match the old ring
Look for: Common faucet sizes in both inch and metric; Rubber or silicone rated for water; A size chart so you can measure.
- Who it's for
- Someone comfortable measuring the old rings.
- Honest downside
- You cannot match the ring sizes. A kit made for your faucet saves the guessing.
Replacement faucet cartridge for your model
Fixes: handle leaks and drips from the spout tip
Look for: Matches your faucet's brand and model number; Comes with its own seals; Listed as a direct replacement.
- Who it's for
- Water leaks at the handle, or the spout still drips after new rings.
- Honest downside
- You cannot identify your faucet brand. Bring the old cartridge to a hardware store to match it.
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How we picked: How we picked: this page is based on faucet repair guides from plumbing and home improvement groups, parts instructions from makers, and the fixes owners report in reviews. We do not test products by hand.
Match your leak to the fix
- Base, only while running: spout O-rings.
- Base, always wet: mounting nut, deck gasket or supply line.
- Handle: cartridge or handle seal.
- Spout tip drips when off: cartridge or seat.
- Under the sink: supply lines or shutoff valves.
What to skip
Caulk, plumber's tape and petroleum jelly
Caulk around the base hides a leak for a week and lets water rot the cabinet below. Plumber's tape is for threaded joints, not for O-ring seals. Petroleum jelly can swell some rubber. Fix the seal, and do not paint over it.
Frequently asked questions
Why is my kitchen faucet leaking at the base?
How do I fix a kitchen faucet handle leak?
How do I know which O-rings to buy?
Why is my kitchen faucet leaking when it is off?
Related problems
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