Why Does My Shower Gurgle When The Toilet Is Flushed?

Did you hear something?

We scour the web for questions to pose to our Contractor in addition to the ones we get from our readers. This week, we asked Randy why a homeowner might hear a “gurgle” in the shower when the toilet is flushed. He responded that there might be a couple of different reasons why this might happen. If the shower was not plumbed correctly and lacked a p-trap that allows air to come up through the drain, one might find this problem. Additionally, a vent pipe could be blocked causing the same issue. What happens during the flush is that the water will displace the air in the pipe and it needs to be replaced, or a vacuum will occur, and the water will not go anywhere. Hence the importance of proper venting in plumbing. Compare it to turning a 5 gallon water bottle upside down. With no vent, it gurgles as the water tries to pour out, whereas if you were to make a hole in the bottom of the bottle, the water would escape much quicker and with no gurgling.

Our resident expert for this post: Randy Ritzenthaler

Leave a Comment