When a toilet bubbles or gurgles, it indicates that negative air pressure (suction) is building up in the drain line. The negative air pressure will eventually release, pushing air backward through the drainpipe and into the toilet bowl. When this occurs, the water in the bowl will bubble and you may hear a gurgling noise. Sometimes the toilet may even flush itself.
The buildup of negative air pressure is caused by a clog in one of two areas: somewhere in the drain system, which could be close to the toilet or farther down the sewer line that connects to your community’s sewer system or septic tank, or in your home’s vent stack (the pipe that allows sewer gases to escape through the roof). Depending on the cause, it could be a DIY fix, or you might need a plumber. We can help diagnose the problem and provide recommended solutions.