Why Does My Toilet Gurgle?

For some homeowners at irregular intervals, one of their toilets gurgles violently until all of the water has drained out of the bowl. Sometimes, this seems to happen whenever one of the tubs was draining, or when the clothes washing machine would discharge the load of wash water.

Why does this happen, and how is the toilet connected to the washer and bathtub?

When this happens, often the culprit is a blocked plumbing vent. Do you know those small pipes that stick out of the roof to exhaust sewage odors? Well, they have another job: they equalize the air pressure in the drainpipe so wastewater flows freely.

You can see this principle at work with straws. When you stick one end of a straw into a glass of liquid and cover the other end with your finger, assuming you keep your finger in place, you can take the straw out of the liquid, but the liquid inside the straw doesn’t come out unless you remove your finger.

In that case, the liquid drains out of the straw immediately. Most of us have all tried this trick at least once.

What’s Blocking the Roof Vent?

Now back to your gurgling toilet: much like your finger on the straw, an object blocking your roof vent can cause the same effect, whether it’s ice from a rare Austin ice storm, leaves, debris, or even an animal carcass.

The result? Whenever there’s a lot of water going down the drain at once, it sucks the water out of your toilet, and it can also do the same to the traps underneath your sinks. The blockage can make your tub drain fairly slowly too.

Removing the Obstruction

As plumbers, we can remove any such obstruction by getting on your roof and running a snake down through your vent system. But, to prevent the problem from occurring again, we have to figure out exactly what’s causing it.

For example, if rodents are to blame, we may need to cover the end of the pipe with hardware cloth, which is held in place by a hose clamp.

To schedule a service call from an Austin plumber, contact us today!