Gurgling Noise from the Sink Drain When the Dishwasher Operates

Gurgling

• When you hear gurgling noises coming from your sink drain when the dishwasher operates, it usually occurs toward the end of the unit’s washing cycle. The gurgling sound lasts for a few minutes then disappears. It can occur whether you have a garbage disposal or not. If you hear the gurgling at the very beginning of the cycle, then you probably don’t have a garbage disposal installed and your kitchen sink has an S-line style drainpipe installed.

Causes

• The most common cause of gurgling in the sink when the dishwasher operates is the dishwasher draining into your sink. When the dishwasher disposes of wash water, it dumps it directly into either the sink drain or the garbage disposal. The sound of all the water filling up the drainpipe causes gurgling. If you hear the noise and the dishwasher isn’t draining, then the S-line isn’t venting properly and shifts in pressure in the pipe are causing the gurgling sound. The noise is more irritating than anything else.

Solutions

• If the gurgling sound is caused by the dishwasher draining, it is nothing to worry about. If you find the sound irritating, place a drain cover in the sink before you start up the dishwasher to muffle the sound. If the sound is caused by improper venting of the S-line, replace that section of pipe with one known as a P-line. If you prefer not to do that, then installing an automatic valve vent on that section of pipe will make sure it vents properly.

Considerations

• S-line-style drain traps were common years ago, but most municipalities require new construction to have P-line pipe sections now. If you do not know how to switch out pipes or install an automatic valve vent on your own, contact a plumbing professional. A plumber can make the changes and make sure that your dishwasher is still able to drain properly into the pipe.