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Writer's pictureJustin Shook

What Causes a Toilet to Run On and Off: Common Causes and Expert Solutions for the "Phantom Flush"

Updated: Sep 26, 2023



A toilet that runs intermittently can be a frustrating problem for homeowners. Not only is it annoying to hear the sound of running water when you're trying to sleep or relax, but it can also be a waste of water and money on your water bill. If you have a leaky toilet, you are not alone! An intermittently running toilet, or a phantom flush, is one of the most common plumbing issues homeowners face. There are several reasons why a toilet may run intermittently, and it's important to understand the causes and potential solutions to this problem. The good news is that these solutions can be performed by most homeowners with minimal tools and experience. If you prefer not to troubleshoot and deal with the hassle, your local plumber can quickly diagnose and take care of the issue for you.





Faulty Flapper Valve


One of the most common reasons for a toilet to run intermittently is a faulty flapper valve. The flapper valve is located at the bottom of the toilet tank and is responsible for controlling the flow of water into the toilet bowl. If the flapper valve is not working properly, it can cause water to leak into the bowl, which will result in a running toilet. To fix this issue, the flapper valve should be replaced.


Malfunctioning Fill Valve


Another common cause of a running toilet is a malfunctioning fill valve. The fill valve is located at the bottom of the toilet tank and is responsible for controlling the water level in the tank. If the fill valve is not working properly, it can cause water to overflow into the bowl, resulting in a running toilet. To fix this issue, the fill valve should be replaced.


Misaligned Flush Valve


A third cause of a running toilet is a clogged or misaligned flush valve. The flush valve is located at the bottom of the toilet tank and is responsible for controlling the flow of water into the toilet bowl. If the flush valve is clogged or misaligned, it can cause water to leak into the bowl, resulting in a running toilet. To fix this issue, the flush valve should be cleaned or realigned.


Worn-out Toilet Flapper Chain


Another possible cause of a running toilet is a worn-out toilet flapper chain. The flapper chain is located in the toilet tank and connects the flapper valve to the flush handle. If the chain is worn out, it can cause the flapper valve to not close properly, resulting in water leakage into the toilet bowl, causing the toilet to run intermittently. To fix this issue, the flapper chain should be replaced.


Bad Toilet Tank Ball


Lastly, a running toilet can also be caused by a malfunctioning toilet tank ball. The tank ball is located in the toilet tank and is responsible for controlling the flow of water into the toilet bowl. If the tank ball is not working properly, it can cause water to leak into the bowl, resulting in a running toilet. To fix this issue, the tank ball should be replaced.


In conclusion, a toilet that runs intermittently can be caused by several factors such as a faulty flapper valve, malfunctioning fill valve, clogged or misaligned flush valve, worn-out toilet flapper chain, and malfunctioning toilet tank ball. The good news is that most of these issues can be fixed easily by most homeowners with minimal tools and experience. If you're unsure of the problem or are not comfortable attempting the repair yourself, it's always best to call a plumber to diagnose and fix the issue. Premium Rooter Plumbing Services is ready to fix your plumbing problems!

(Disclaimer: Premium Rooter Plumbing Services takes no responsibility for any and all damages or injuries to persons or property resulting from following the steps in this article. For professional installations, contact Premium Rooter Plumbing Services.)


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