Why is there a loud droning noise every time I flush my toilet?
By loud “droning noise,” I am assuming when you flush, the pipes are making a groaning or shaking sound. This is called “water ramming” or “air hammering.” It is caused usually by a leak drawing air into the line and forming an air bubble which bounces around inside the pipe and causes noise. Make sure the shut off valve under the toilet is fully open and check around the house inside and out for the slightest drip. This is where the air is entering the system. You can also install an “Air Chamber”, which is essentially a piece of copper pipe about 18″ long that is capped. This allows the air bubble to enter this dead end and dissipate.
To understand the physics of plumbing systems and how they contribute to the strange and unusual noises we sometimes hear, it is best to put into perspective the the forces at play. Within the plumbing system you have water, pressure, and air all operating in different levels, various intensities, in different places, nooks and crannies of your home. When water is rushing like a runaway locomotive and slamming into an air pocket, you will indeed a hear a rather loud noise that sounds much like a train roaring to a stop. Is this noise and others noises you may hear in your walls and floors and ceilings something that you will always have to contend with? Is there anything you can do about it? The honest answer is yes and yes. To varying degrees, you will always hear plumbing system related noises. And the cause of these noises is most often internal to what is going on within a closed system, you pipes. Though that is not always the case. Sometimes you may find that a pipe is not securely latched in place and that movement can cause a bit of a rattling noise. To learn more about what actions you can take to minimize the noises you may hear throughout your home, please go visit some of our articles on the topic.