Sink cartridge faucet keeps dripping — cartridge

Use only checks that match the exact appliance or system and its official guide.

1. Check 1

   From a dry, stable position, wipe the exposed faucet and cabinet surfaces, turn the faucet on once, turn the handle or handles fully off, and watch where the first new water appears without removing trim.

   Expected result: Classify the leak as a continuing drip or stream from the spout, water around the handle or faucet base while running, water under the sink at a supply or stop-valve connection, or no repeatable leak.

   Next step: Take a close photo of the leak location and continue only with the matching branch below; if water is reaching the cabinet, wall, floor, or electrical equipment, stop use and arrange service.

   Stop if: Stop for active flooding, water near electrical equipment, a split hose, unstable cabinetry, or any need to reach through standing water.

   Why this matters

   Why: A spout drip with the handle off makes an internal cartridge, seat, or seal more likely. A handle or base leak makes an external seal, bonnet, body, or spout connection more likely; an under-sink leak is a supply-side problem rather than proof that the cartridge is bad.

2. Check 2

   Record whether the faucet has one handle or separate hot and cold handles, and photograph any visible manufacturer mark, model label, faucet shape, and underside label from ordinary safe access; do not remove the handle just to identify the cartridge.

   Expected result: Note a readable model number, only a brand or logo, two separate handles, or no usable identity information; also record which handle or side is associated with the drip on a two-handle faucet.

   Next step: Use the exact model in the manufacturer's parts lookup or provide the photos to the manufacturer or plumber; if identity is unknown, do not order a generic cartridge or start disassembly.

   Stop if: Stop if identifying the model would require removing a stuck handle, cutting trim, disconnecting a hose, or entering a wet or cramped unsafe space.

   Why this matters

   Why: Handle count changes the diagnostic path, and the exact model is needed to select the correct cartridge or valve. A familiar-looking replacement is not evidence of fit because manufacturers use multiple cartridge designs.

3. Check 3

   From outside the cabinet, inspect the accessible hot and cold shutoff valves and supply hoses; close a valve gently only if it turns normally, is dry and intact, and you know it is the faucet supply shutoff.

   Expected result: After a normal gentle closure, note whether the faucet flow stops, slows but continues, or the valve cannot be operated safely; do not repeatedly cycle a corroded stop.

   Next step: If isolation fails or the valve condition is uncertain, leave the faucet assembled, avoid forcing it, and contact a plumber; if isolation succeeds, open the faucet briefly to relieve residual pressure only while keeping the area dry and controlled.

   Stop if: Do not force a seized valve, loosen a supply connection, remove a cartridge, or continue if water cannot be isolated or begins escaping from the stop or hose.

   Why this matters

   Why: A stop that isolates the faucet creates a safer boundary for a model-specific repair. A stop that does not isolate the faucet, leaks at the stem, or cannot be turned safely leaves the line pressurized and makes cartridge disassembly a service task.

4. Check 4

   With the faucet still assembled, observe one controlled off-to-on-to-off cycle after recording the initial condition, and note whether handle movement changes the drip, without tightening hidden hardware or repeatedly operating a damaged control.

   Expected result: Record whether the spout begins dripping only after shutoff, the drip changes when the handle is moved, water appears around the handle or base only while flowing, or the symptom is unchanged.

   Next step: Match the observed pattern to a symptom-led branch and give the model, photos, handle count, and timing to the manufacturer or plumber before selecting parts.

   Stop if: Stop if the handle binds, breaks, sprays water, the leak rate increases, or the faucet cannot be returned to a controlled position.

   Why this matters

   Why: A drip that persists after shutoff supports a closure problem in the cartridge or valve assembly. A handle-dependent or base leak points more toward a seal, bonnet, spout connection, or body issue; unchanged behavior despite handle movement does not identify a replacement part by itself.

5. Check 5

   Inspect only visible surfaces and record mineral scale, corrosion, a hard or loose handle, a recent cartridge replacement, missing trim, or evidence of prior sealant; do not pry the cartridge or scrape inside the valve body.

   Expected result: Note whether the faucet is clean but still dripping, has scale or debris at the visible outlet, shows corrosion or damage, or started dripping immediately after a repair.

   Next step: Save the old part and repair documentation if already removed, photograph the valve and handle, and request model-specific instructions or professional diagnosis when the drip persists or the body is damaged.

   Stop if: Do not force a retaining nut, scrape a sealing surface, add unapproved sealant, or continue disassembly when the valve body or fastener is corroded.

   Why this matters

   Why: Scale or debris can affect a seal, but corrosion, a damaged valve body, incorrect orientation, an incompatible cartridge, or debris left after service can also cause a post-repair drip. A visible clue alone does not prove which internal part fits.