Have you ever been sitting quietly watching TV and heard your toilet flushing all by itself in the other room? This can be a little eerie, to say the least, but rest assured it’s not all that uncommon, and it signals an issue with the flapper.
The flapper is that large, round rubber thing that rests at the bottom of your toilet tank. Its job is to open and close to allow water to flow into the toilet bowl every time you flush. The flapper is prone to wear and tear, and when this happens, your toilet flushes by itself.
As alarming as it is that your toilet flushes by itself, you can be sure your house is not haunted. Instead, it just means you are going to need to get your hands dirty to fix the issue. Below, I’ll explain why toilets flush by themselves and give you a step-by-step guide to repairing the problem.
So, what causes a toilet to flush on its own?
What Causes A Toilet To Phantom Flush
Expert plumbers jokingly call the random flushes a toilet makes by itself ghost or phantom flushes. There is really only one common cause for phantom flushing, and that’s an issue with the flapper.
Leaking Flapper Seal
The flapper inside the toilet is usually made of rubber, which everyone knows deteriorates over time when submerged in water. Since the flapper’s job is to create a watertight seal between the toilet tank and bowl, when it deteriorates, the seal can be broken, allowing water to leak into the bowl. When the water level inside the tank drops far enough, the toilet will flush itself.
Flapper Chain Too Tight
The flapper is controlled by the flush handle, which is connected to the flapper via a plastic or metal chain. The chain must be short enough to open the flapper enough when the handle is pressed and long enough to allow it to close all the way at the end of a flush. If the chain is too short, the flapper cannot close and create a watertight seal, thus allowing water to leak into the bowl.
How To Fix A Toilet That Flushes Itself
If you notice that your toilet’s flapper is damaged or deteriorated in any way, replacing it should stop your toilet’s phantom flushing. Follow the steps below to replace the flapper.
- Turn off the water to the toilet. The shut-off valve is located underneath or behind the toilet tank.
- Flush the toilet. This will drain the water inside the tank so you can get to the flapper easily.
- Remove the old flapper.
- Clean the area on the bottom of the tank where the flapper rests. Mineral deposits and other debris can build up here and cause the new flapper to not seal properly.
- Install the new flapper following the manufacturer’s instructions.
- Attach the chain to the new flapper making sure the length is just right. Don’t allow slack in the chain, but make sure it isn’t too tight either.
- Turn the water back on, making sure to turn the knob all the way open so there is enough water pressure in the tank.
Note: Every toilet model is different, so the flapper installation may vary. Be sure to follow the manufacturer’s instructions for installation. If you have questions or need further assistance, do a Google search for the make and model toilet you have to find more detailed instructions and/or visual help in installing your new flapper.
Other Possible Causes for the Toilet to Flush Itself
Sometimes, a ghost flushing toilet isn’t caused by a worn flapper. While a worn flapper is the most common cause, there might be another reason your toilet is flushing itself.
Worn Flush Valve Seal
This seal closes the flush valve. When it fails, it can allow water to leak into the bowl, causing the toilet to flush itself when the water level gets too low in the tank.
The Toilet Float Needs to Adjusting
The toilet float tells the toilet when to stop filling, so it doesn’t overflow. If the float is adjusted too high and too much water enters the tank, the toilet may flush itself to stop it from overflowing. This is a simple fix as all you need to do is adjust the float to lower the water level.
Refill Tube Not Securely Fitted
The refill tube returns water to the toilet bowl after a flush. If this refill tube is not positioned correctly, your toilet may flush by itself.
Toilet That Keeps Flushing Itself – Solved
Typically, a toilet that keeps flushing itself can be fixed by simply cleaning the area where the flapper rests or replacing the flapper if it appears worn or damaged. If the flapper chain seems to be too short, adjusting the length a little longer can help the flapper seal better so the toilet doesn’t continue to flush on its own.
In some cases, the flapper may not even be the issue at all. Rather, a worn flush valve seal, improperly adjusted float valve, or misaligned refill tube may also cause a toilet to flush by itself. Although a little startling when it happens the first time, there is no reason to worry about a phantom flushing toilet as diagnosing and repairing these issues is quick and easy with the knowledge I’ve provided above.
Toilets Run Between Flushes
Another common issue related to the toilet is one that runs between flushes. This issue has some of the same causes as a toilet that flushes by itself. A worn flapper or a flapper chain that’s too short are often the causes for a constantly running toilet, although some other causes include a float valve or refill tube that is improperly positioned or a malfunctioning flush mechanism. If your toilet runs intermittently or constantly after flushing, you can diagnose the issue and find a resolution here Why Your Toilet Randomly Runs and How To Fix It.
Why A Toilet that Flushes By Itself Is a Problem
While a toilet that flushes by itself is a little creepy, a lot of people tend to ignore it and put off fixing it because of its seemingly harmless nature. The same holds true for a toilet that runs after flushing. The issue doesn’t seem to be a huge problem, so many people allow it to go on longer than they should.
The reason a self-flushing or intermittently running toilet is a bad thing, though, is because both issues waste hundreds, if not thousands, of gallons of water a year, according to the Environmental Protection Agency (EPA). That means you’re paying more for water than you should, literally throwing money down the drain.
You may also be interested in reading How To Flush A Toilet With A Broken Handle
As a retired Master Plumber Jamie has over 30 years of hands-on experience, making his plumbing knowledge second to none. He has also worked on both residential and commercial HVAC installation and repair projects.