Why do I hear gurgling in my sink when I flush the toilet?

The gurgling you hear from the sink when you flush the toilet may sound innocuous, but it can spell trouble if you let it persist. It means that the pipes aren’t properly vented, which can lead to slow water flow and eventual blockages. Covering the sink drain keeps the force of the plunger in the pipes.Click to see full answer. Thereof, why does my sink gurgle when I wash clothes?Well, sink gurgling is caused by pressure difference inside drain pipes of your plumbing system. This means that your washing machine drain is probably connected to the sink drain so that’s why you hear your sink gurgle only when your washing machine is on.Likewise, what makes a sink drain gurgle? Drain gurgling can happen for several reasons. It can either be from a partially clogged drain or the drain not being properly vented. If the drain isn’t properly venting, air will fill the vacuum created by the water and cause the gurgling sound, which is the sound of air rushing past the sink’s P-trap. In this way, why does one gurgle when I flush the toilet? Bubbles in the toilet, a toilet that drains slowly, or one that gurgles is telling you something specific: You have a blockage. For water and waste to flow through your pipes, the air pressure has to be just right. A block causes negative air pressure, or suction, in your plumbing.What does a gurgling sink mean?That gurgling sound in your sink means there is an issue with the air in the drain pipes. If the gurgling happens only when you use the sink, you probably should focus on the sink vents, but if it happens when you flush a toilet or drain the tub, you need to examine the entire vent system.