Symptoms
- Sink drains slower than usual after using disposal
- Standing water lingers after grinding
- Gurgling sound as water drains
- Smell of trapped food waste
Likely causes
- CommonGrease or food buildup in the trap or drain lineGrease coats pipe walls and narrows the passage over time.
- CommonPartial clog from fibrous or starchy foodRice, pasta, and potato peels expand and stick to pipe walls.
- PossibleDisposal not fully clearing food into the drain lineRunning it dry or too briefly leaves debris sitting in the trap.
- Less commonVent stack blockage causing slow drainageA blocked roof vent can slow drains throughout the house.
What to do
- Run hot water for a minute with the disposal off to see if it's a general drain issue, not the disposal.
- Run the disposal again with cold water flowing to clear any residual debris.
- Try a manual plunger with the dishwasher air gap or hose clamped off to build suction on the disposal drain.
- Remove the trap (P-trap) under the sink over a bucket and clear out any visible debris.
- Use a drain snake through the trap arm if a plunger doesn't clear it.
- Avoid chemical drain cleaners, which can damage disposal seals; use them only as a last resort if at all.
- Reassemble the trap, run water, and confirm drainage speed is back to normal.
Tools and parts
- Plunger
- Bucket
- Adjustable pliers
- Drain snake (optional)
P-trap replacement kitSearch: “sink P-trap kit”
When to call a pro
If snaking doesn't help or multiple drains in the house are slow, call a plumber to check the main line or vent stack.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.