Kitchen sink bubbles when dishwasher runs

Drain or fixture making gurgling or bubbling sounds

Quick Answer:

If you hear bubbling or gurgling from the kitchen sink while the dishwasher runs, it usually means air and water are moving irregularly through the drain system. Do a few simple checks to see whether water is being sucked out of traps or forced back through them. If the noise keeps coming back or several fixtures act up, have a plumber inspect the venting and main line safely.

Why This Happens

  • Partial clog in the sink trap, branch drain or dishwasher hose can force air and water to move unevenly, producing gurgles.
  • A blocked vent stack or venting problem causes pressure changes in the drain line. That can pull water from traps (suction) or push air/water back into them (pushback).
  • Main sewer line issues or tree root intrusion can create backpressure that shows as bubbling in fixtures when another appliance runs.
  • If the problem comes and goes, see Gurgling only sometimes for more about intermittent noises and what that usually means.

Step-by-Step What to Do

Step 1 — Recreate the issue with the dishwasher alone

  • Run the dishwasher through a normal cycle while no other faucets or appliances are on.
  • Stand near the sink and listen at the drain opening for the gurgling sound. Note when it happens during the cycle (draining, filling, pump running).

Step 2 — Run the triggering fixture alone, then with another fixture

  • Turn on the kitchen sink alone and watch for noise or slow drainage.
  • Then run another nearby fixture (a bathroom sink or a tub) at the same time as the dishwasher to see if the sound changes or gets worse. This helps reveal venting or shared drain issues.

Step 3 — Note whether water level in nearby traps moves

  • Look into sink basins and other nearby drains while the dishwasher or fixtures run. If the water level in the P-trap drops, that suggests suction through the venting system.
  • If water surges or bubbles up, that suggests pushback from a partial blockage or pressure buildup.

Step 4 — Listen at the drain opening to identify suction vs pushback

  • Place your ear over the sink drain (do this safely — don’t block your ear with wet hands). A sucking or whistling sound usually means air is being drawn past the trap. Bubbling or splashing noises indicate pressure pushing back through the trap.
  • Match what you hear with the trap movement you observed in Step 3 to decide which is happening.

Step 5 — Do simple visible checks

  • Remove and inspect the sink strainer for debris and hair. Clear what you can by hand or with a brush.
  • Check the dishwasher drain hose connection under the sink for kinks or loose clamps.
  • Run a slow flow of water and see whether drainage improves — that can flush small buildups.

Step 6 — Stop and call a pro if you’re unsure

  • If the sounds continue, traps are losing water, or multiple fixtures are affected, stop attempting complex fixes and contact a plumber to check venting and the main line.

What Not to Do

  • Don’t pour harsh chemical drain cleaners down the sink. They can damage pipes, harm seals, and make repairs more hazardous.
  • Don’t cap or block vent pipes yourself or try to alter the roof vent. Tampering with vents can create dangerous sewer gas buildup and won’t fix underlying blockages.
  • Don’t ignore symptoms that involve more than one fixture — if multiple drains gurgle or back up, a plumber should check venting and main line conditions rather than relying on DIY fixes.

When to Call a Professional

  • When the noise keeps returning after basic checks and simple cleaning.
  • If you notice sewer smell, persistent trap water loss, gurgling in several fixtures, or any backups (water coming up in other drains or toilets).
  • If you’re unsure whether the issue is a venting problem or a main line blockage — a licensed plumber can inspect the vent stack safely and use camera inspection on the drain line if needed.

Safety Notes

  • Sewer gas can be dangerous. If you smell rotten eggs or suspect a significant leak, ventilate the area and call a professional immediately.
  • Do not climb onto the roof to access the vent stack unless you are experienced and have proper fall protection. Roof work is risky and best left to professionals.
  • Wear gloves and eye protection when checking traps or clearing debris. Avoid breathing fumes from any chemicals; prefer mechanical cleaning and a plumber’s help for tough clogs.

Common Homeowner Questions

  • Will the gurgling stop on its own?
    Often a one-time gurgle from a small clog can clear, but repeated gurgling usually needs inspection.
  • Can the dishwasher damage plumbing?
    Not normally; but a blocked drain or improper hookup can cause pressure and noises that should be corrected.
  • Is it related to the toilet?
    Yes — if you see bubbles in the toilet when other drains run, such as with Toilet bowl bubbles when sink drains, that points to shared drain or vent issues that need a plumber.

For more related articles, see the Gurgling Sounds From Drains or Fixtures hub.

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