A kitchen sink is a handful of simple parts, and most leaks and clogs come from one of them. Knowing the name of the part under the cabinet makes a sink repair faster, and it tells you which problems are a washer or a trap and which ones mean a new fixture.
Basket strainer
The basket strainer is the metal cup in the bottom of the sink. It catches food and seals the drain opening. A leak here shows up as water under the sink only when the basin is full, because the seal between the strainer and the sink is wet only then. The fix is a new plumber's putty or gasket, not a new sink.
Tailpiece
The tailpiece is the straight tube that drops from the strainer (or from the disposal) toward the trap. Slip nuts at each end are hand-tight plus a quarter turn. A drip at a slip nut is one of the most common under-sink leaks, and it is a standard sink repair.
P-trap
The P-trap is the U-shaped bend under the sink. It holds a little water so sewer gas cannot come up the drain. Most kitchen clogs of grease and food sit in this bend. It comes apart by hand for cleaning. If every sink in the house is slow, the clog is not in this trap. It is farther down the line.
Supply lines
Supply lines are the flexible hoses that carry hot and cold water from the shutoff valves up to the faucet. A bulging, rust-stained, or actively spraying line should be replaced. Shut the valve under the sink first. If the valve itself will not turn, shut off the house water and call a plumber.
Faucet
The faucet is the spout and handles on the deck. Drips usually come from a cartridge, washer, or O-ring inside, which is a repair. A faucet that is corroded through, or that leaks from the base no matter what, is a replacement. We install faucets you already bought or help you pick one. That work is on our fixture installation page.
Shutoff valves
Shutoff valves sit on the wall under the sink, one for hot and one for cold. They let you work on the faucet without killing water to the house. Older valves seize. Forcing a stuck valve can snap it and flood the cabinet. If it will not turn with firm hand pressure, leave it and call.
Air gap
An air gap is the small chrome fitting on the sink deck beside the faucet, required on many dishwashers. It keeps dirty dishwasher water from siphoning back into the water supply. If the dishwasher drains onto the counter, the air gap or the hose to it is clogged. It is not the dishwasher pump until that hose is checked.
Garbage disposal
The disposal hangs under one basin and connects to the tailpiece and the trap. Jams, humming without spinning, and leaks at the flange are the usual failures. Reset buttons and hex-key unjamming are covered in our garbage disposal guide. A leaking flange or a seized unit is a replacement, not another reset.
Which part is actually leaking?
Match the symptom to the part:
- Drip from the spout: faucet cartridge or washer.
- Water only when the basin is full: basket strainer seal.
- Drip at a slip nut: tailpiece or P-trap.
- Spray from a hose: supply line.
- Leak at the dishwasher fitting on the deck: air gap or its hose.
- Water from the disposal body: flange or the unit itself.
People's Choice Plumbing repairs and replaces these parts across Jupiter, Palm Beach Gardens, and Martin County. We answer the phone 7 days a week. Service calls are Monday through Friday, 7 AM to 6 PM.
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Frequently Asked Questions
What are the parts of a kitchen sink?
The main parts are the basket strainer, tailpiece, P-trap, hot and cold supply lines, faucet, shutoff valves, dishwasher air gap, and, on many sinks, a garbage disposal. Most leaks and clogs come from one of those.
What is the P-trap under a kitchen sink?
The P-trap is the curved pipe that holds water so sewer gas cannot enter the kitchen. Grease and food clogs usually sit in that bend, and it can be taken apart to clean.
Why does my kitchen sink leak only when it is full?
That pattern usually means the basket strainer seal, between the metal cup and the sink basin, has dried out. Water reaches that joint only when the basin is full.
What does a shutoff valve under the sink do?
It stops hot or cold water to that faucet so the supply line or faucet can be worked on without shutting off the whole house. A valve that will not turn should be left alone so it does not break open.
What is the air gap next to the kitchen faucet?
It is the dishwasher's backflow preventer. If the dishwasher empties onto the counter, the air gap or the hose connected to it is often clogged.
Is a leaking kitchen sink a repair or a new sink?
A drip at the faucet, supply line, tailpiece, or P-trap is a sink repair. A cracked basin or a faucet that is corroded through is a replacement.