Kohler sink faucet keeps dripping: What to check and what to do next

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

1. Check 1

   Dry the faucet, sink deck, and visible supply area, then turn the faucet off and watch from a safe position for the first new wet point: spout tip, under-handle area, spout base, spray hose, supply connection, or below the sink.

   Expected result: The drip is at the spout tip, under the handle, around the base, from a hose or supply connection, or cannot be localized because water spreads across the deck or cabinet.

   Next step: Photograph the first wet point and choose the matching branch. If the leak is active, reaches the cabinet or electrical equipment, or cannot be isolated, close the accessible shutoff valves and call a plumber.

   Stop if: Do not keep operating the faucet to trace a large leak, touch wet electrical equipment, or remove a connection while water is not isolated.

   Why this matters

   Why: The wet point selects a different check. Spout-tip drips suggest aerator or valve behavior; under-handle or base leaks suggest seals, valve or cartridge, check-valve or spacer components; hose or supply leaks are connection problems rather than proof of a bad cartridge.

2. Check 2

   If water is coming from the spout tip, close the handle fully and observe whether the drip stops after retained water drains or continues steadily with the faucet off; do not open the faucet body for this timing check.

   Expected result: The drip stops after a short period, continues throughout the day, changes when the handle is moved, or the water is actually coming from under the handle or base.

   Next step: Use the temporary-drip branch for an aerator check. For a continuous drip, record whether the faucet is single-handle or two-handle and proceed to model and water-isolation preparation before considering internal service.

   Stop if: Do not repeatedly move a loose or stiff handle, force the cartridge, or disassemble the faucet while the supply remains pressurized.

   Why this matters

   Why: A brief post-shutoff drip can be aerator debris or retained water. A continuous drip with the handle off makes a valve or cartridge sealing problem more likely; a different wet point requires a different repair path.

3. Check 3

   Only if the drip is brief and from the spout tip, remove the aerator only as the exact Kohler faucet instructions allow, inspect its screen for scale or debris, rinse it, and reinstall it without cross-threading or overtightening.

   Expected result: The screen is visibly scaled or dirty, the aerator is damaged or seized, the drip stops after cleaning, or the drip continues all day after the aerator is clean.

   Next step: If cleaning resolves the brief drip, monitor the faucet. If the drip persists, stop repeated cleaning and identify the faucet model before a valve or cartridge service; call a plumber if the aerator cannot be removed without force.

   Stop if: Do not use a drill, knife, abrasive tool, chemical descaler that the faucet instructions do not allow, or force a stuck aerator against the faucet finish.

   Why this matters

   Why: A dirty aerator can explain a temporary post-shutoff drip. A continuous leak after a clean aerator points toward the valve or cartridge rather than the screen, while a damaged or seized aerator needs model-specific replacement or service.

4. Check 4

   With the water supply isolated if tools or internal parts are involved, inspect the handle attachment, faucet body, spout base, and any visible weep opening for mineral residue, a loose handle, damaged finish, or a first wet point below the handle or base.

   Expected result: Water appears under the handle while on or off, around the spout base, at a visible weep opening, or only at an external hose or supply connection.

   Next step: Do not assume a cartridge is the answer for a hose or supply leak. For an internal handle or base leak, use the model-specific parts diagram or arrange plumbing service after the water is isolated.

   Stop if: Do not tighten hidden retaining parts by guesswork, pry trim from the countertop, or continue if the shutoff valve, hose, or mounting hardware is corroded or moving.

   Why this matters

   Why: Kohler associates an under-handle leak while on with seals or O-rings and an under-handle leak while off with the valve or cartridge; base leaks can involve seals, O-rings, bearings, valve or cartridge, or a check-valve or spacer assembly depending on the model.

5. Check 5

   Record the Kohler faucet model or series, whether it is single-handle or two-handle, and whether it has a pull-down, pull-out, sidespray, or touchless assembly; use the faucet documentation or model-identification resources without removing the faucet from the sink.

   Expected result: The model and configuration are known, only a partial identity is available, or the faucet identity cannot be found without dismantling it.

   Next step: Use the exact model to check Kohler's parts diagram and service instructions, or provide photos and the faucet identity to a plumber or Kohler support. Do not order by appearance alone.

   Stop if: Do not remove internal components just to discover the model, and do not substitute a cartridge, O-ring, or hose without verified compatibility.

   Why this matters

   Why: Kohler replacement valves, cartridges, seals, check valves, spacers, aerators, and hoses are configuration-specific. An incomplete identity makes a generic part an unsafe compatibility assumption.

6. Check 6

   After a model-approved aerator cleaning or documented water-isolation step, make one controlled leak check around the spout tip, handle, base, and under-sink connections; do not leave the cabinet unattended while testing.

   Expected result: The drip is gone, returns only briefly after use, continues with the handle off, appears under the handle or base, or leaks from a hose, supply, or shutoff connection.

   Next step: Keep the affected supply isolated when practical and arrange plumbing service for any continuous, active, inaccessible, or recurring leak. Give the plumber the wet-point location, timing, faucet model, and parts already inspected.

   Stop if: Do not leave a cabinet wet, operate with a loose or leaking connection, force the handle, or continue internal repair when water cannot be isolated.

   Why this matters

   Why: A resolved brief spout drip supports an aerator or retained-water explanation. A continuous or connection leak requires the corresponding compatible seal, valve, cartridge, hose, fitting, or plumbing diagnosis; repeated tightening can damage the faucet or connection.