Quick answer
A kitchen sink smell usually comes from food and grease in the garbage disposal, especially under the rubber splash guard, or a grease film inside the drain. A sewage smell points to a dry or leaking trap, a blocked vent, a partial clog, or a dishwasher drain hose with no high loop. Clean the splash guard, flush with hot soapy water, and check the dishwasher hose. HomeServe puts drain cleaning at $100–$275. Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed November 4, 2026· Next review May 2027
A kitchen sink that smells bad is usually telling you about food: grease and scraps in the garbage disposal, or a film of grease inside the drain. A sewage or rotten-egg smell is different and points to the trap, the vent or the dishwasher connection.
Match the Smell to the Cause
| Smell | Likely cause |
|---|---|
| Rotting food | Food and grease in the garbage disposal, under the splash guard |
| Sour or musty, from the drain | Grease and biofilm coating the drain pipe |
| Sewage | Dry or leaking trap, blocked vent, or a partial clog further down |
| Sewage only when the dishwasher drains | Dishwasher drain hose without a high loop or air gap |
| Musty, from the cabinet | A slow leak under the sink and mold; see mold under the kitchen sink |
Clean It in This Order
- 1Clean the disposal splash guard. Lift the rubber flaps and scrub underneath; that is where most of the smell lives.
- 2Grind ice and a little dish soap in the disposal, then run cold water for 30 seconds.
- 3Flush the drain with very hot water and dish soap to loosen grease. Avoid boiling water if the drain is PVC.
- 4Check the dishwasher hose. It should loop up high under the counter, or run to an air gap, so drain water cannot sit in it.
- 5Look under the sink with a flashlight for drips at the trap, the disposal or the supply lines.
Talk to a plumber about this
One call reaches a plumbing company taking calls in your ZIP.
When It Is the Drain Line
A smell that comes back within days of cleaning, together with a slow drain or gurgling, means grease has built up further down the line. See kitchen sink not draining and drain gurgling.
What a Repair Costs
HomeServe puts drain cleaning at $100–$275. A disposal that leaks or will not grind is covered on garbage disposal repair.
When to Call
Call if the smell is sewage, if it returns after cleaning, or if you find water under the sink. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
Why does my kitchen sink smell like rotten food?
Food and grease trapped in the garbage disposal, most of it under the rubber splash guard. Scrub under the flaps and grind ice with dish soap.
Why does my kitchen sink smell like sewage?
A dry or leaking trap, a blocked vent, a partial clog further down the line, or a dishwasher drain hose that lets dirty water sit in it.
When should I call a plumber for a smelly sink?
If the smell is sewage, comes back within days of cleaning, comes with a slow or gurgling drain, or you find water under the sink.
Sources
Methodology: How we source and verify data · Report an error
Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.