Moen 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 spout, handle, faucet base, underside of the deck, shutoff valves, and supply lines. With the faucet fully off, observe where the first drop appears and whether it happens only while running, shortly after use, or continuously.

   Expected result: The spout drips while off; water appears around a handle or base; or the first wet point is a hose, shutoff valve, threaded fitting, or faucet connection below the sink.

   Next step: Follow the branch that matches the first wet point, keep the cabinet dry, and photograph the location and timing. Do not order a part from the symptom alone.

   Stop if: Stop if water sprays, the leak is rapidly increasing, the faucet body or hose is split, or water is reaching electrical equipment.

   Why this matters

   Why: A persistent spout drip makes the internal cartridge or seal more likely. A handle or base leak may be a seal or body connection. A below-sink leak points more toward a supply, shutoff, or connection-hose problem and can damage the cabinet even when the spout is dry.

2. Check 2

   Place a towel or container below the leak and close the clearly identified hot and cold faucet supply stops only if they turn normally. If one stop isolates the drip, leave it closed; if both are needed or a stop will not close, use the main water shutoff according to local plumbing guidance.

   Expected result: The drip stops with one supply closed, stops only when both supplies are closed, continues after the faucet stops are closed, or the shutoff itself leaks or will not move.

   Next step: Keep the isolated supply closed and arrange plumbing service if the stop leaks, is seized, or the main shutoff was required. Do not remove a pressurized hose, cartridge, or valve.

   Stop if: Stop for flooding, a seized or corroded stop, active spray, water near electrical equipment, or any fitting that remains pressurized.

   Why this matters

   Why: A one-sided result can identify the hot- or cold-side valve or supply path. A drip that stops only with both supplies isolated can still be internal to the faucet. A failed local shutoff increases flooding risk during repair.

3. Check 3

   Identify the faucet without dismantling it: note single- or dual-handle construction, kitchen or bathroom sink use, deck layout, pullout or pull-down hose if present, and any model marking or paperwork. Compare the model-specific Moen parts sheet or repair guide before selecting a cartridge, O-ring, grommet, or hose.

   Expected result: The model is confirmed, the model is unknown, the faucet has one handle, or it has two handles and separate valve controls.

   Next step: Use the confirmed model guide or provide the model and photos to a plumber or Moen support channel. Do not substitute a cartridge based only on color, handle shape, or a generic part description.

   Stop if: Stop if the model cannot be confirmed, the available guide does not match the installed faucet, or repair would require force or cutting.

   Why this matters

   Why: Moen states that single-handle and dual-handle faucets use different cartridge counts and that its cartridges are not interchangeable. An unknown model prevents a reliable part match even when the symptom sounds familiar.

4. Check 4

   With the supply isolated, inspect only visible connections below the sink and the faucet base for wetness, a split hose, a leaking shutoff, or water tracking from the handle onto the deck. If the spout stream is weak as well as dripping, clean the aerator only according to the exact faucet guide; do not treat aerator cleaning as a cartridge diagnosis.

   Expected result: A shutoff, supply line, or connection hose is wet; water begins at the handle and runs onto the base; the faucet base is wet but the handle is dry; or the external surfaces are dry and the spout still drips.

   Next step: Follow the exact model guide for a clearly identified connection or keep the water isolated and call a licensed plumber for internal valve work. Reopen a supply slowly only after the repair is complete and the area can be watched.

   Stop if: Stop for a cracked body or hose, a fitting that spins or will not seal, a seized handle, or active leakage after a normal gentle correction.

   Why this matters

   Why: A visible below-sink wet point is an external connection or valve path. A handle-to-base path can be a handle seal. A dry exterior with a spout drip makes the cartridge or internal seal more likely. An aerator issue affects flow and does not by itself explain a valve that will not shut off.

5. Check 5

   After an exact model-specific repair or a plumber's work, reopen the isolated supply slowly while watching the spout, handles, base, hoses, shutoffs, and cabinet. Operate the faucet normally, turn it fully off, and wait long enough to see whether a drip returns.

   Expected result: The faucet remains dry when off; drips only when a handle moves; leaks immediately at a connection; or the original drip returns after a short period.

   Next step: Close the supply again for any returning leak, record the exact location and timing, and arrange licensed plumbing service rather than repeatedly tightening or replacing parts by guesswork.

   Stop if: Stop immediately for spraying water, cabinet damage, a cracked body, or a supply stop that cannot isolate the faucet.

   Why this matters

   Why: A dry complete cycle supports that the repair addressed the leak. A movement-related drip suggests a handle or dynamic seal issue. An immediate connection leak suggests an assembly or fitting problem. Recurrence suggests a mismatched or damaged part, debris, or a faucet-body problem.