If a toilet randomly runs for a few seconds and empties without flushing, it's likely the result of a cracked toilet flapper, the chain being caught, the float needing to be lowered, or the refilling tube needing to be repositioned.
A toilet that cuts on and off by itself, or runs intermittently, has a problem that plumbers call a "phantom flush." The cause is a very slow leak from the tank into the bowl. This problem is almost certainly caused by a bad flapper or flapper seat.
If the toilet keeps running or runs intermittently, you're not getting a good seal. Try a different flapper if the toilet won't stop running. If you just can't find a flapper that seals, consider replacing the entire toilet overflow tube/flapper. On most toilets (two-piece), this means removing the tank.
Running noises occur when water leaks out of the tank and into the bowl, and then the tank re-fills with water. These noises should cease as soon as the tank is finished filling.
The most common toilet leak is caused by a deteriorated flush valve (flapper) at the bottom of the toilet tank. If the flapper does not seat properly, water will leak into the toilet bowl. Often this leak will occur without being heard.
If your toilet randomly runs off and on for a few seconds, it is likely due to a broken flapper. While the flapper is supposed to drop down and re-seal the tank when enough water has gone through, a cracked or decaying flapper will allow water to keep flowing through and run periodically.
The most likely cause is capillary action. This happens when a piece of debris, wicks the water out of the bowl and down the drain. It could be something as small as a string. Another possibility is the drain venting in the home is not sized properly, or a clogged vent.
A hissing sound means that the refill valve is still allowing a little bit of water into the tank because it has not shut off like it is actually designed to. So, when you hear your toilet hissing, take the lid off your toilet tank immediately.
While toilet flappers are normally pretty durable, they can wear out over time. The average toilet flapper lasts about 4 to 5 years. It is important that you replace your toilet flapper when needed to prevent damaging leaks.
Will a running toilet stop eventually? As fresh water enters the tank, a mechanism eventually shuts off the water flow and the toilet will stop running. However, when things go wrong with the valve, flapper or overflow then it's best to get it sorted.
If you've tried replacing the toilet flapper but the toilet still runs, the flush valve seat is probably rough or pitted. You can replace the entire flush toilet flapper valve, but it's a big job.
Perhaps the most common reason for a running toilet is an old flapper that needs to be replaced. When flappers get old, they don't seal the way they should, and this allows water to pass constantly from the toilet tank into the bowl.
However, the tradeoff is they corrode over time and will generally need to be replaced about every two years or so. There's more good news: you can replace a toilet flapper yourself! They cost just a few dollars at your local hardware store, and require no specialized tools or training to replace it.
It's happened to nearly all of us — you've walked into your bathroom and noticed a slight hissing sound coming from your toilet tank area. This sound is often ignored, but doing so could cost you with increased water bills over time. A faint hissing sound in the toilet tank is often due to a faulty fill valve.
Issue 2: Prolonged hissing sounds coming from your toilet
To fix this, you'll need to check your float, refill tube and the ballcock/inlet valve. You want to see if your float is sticking or needs adjusting and make sure the refill tube isn't too far inside the overflow tube.
A hissing sound can mean that the refill valve is still letting a tiny bit of water into the tank because it hasn't shut off like it's designed to. The valve shuts off automatically based on the water level in the tank. A faulty valve or one not set properly will keep running.
Low Water in Toilet Bowl
The toilet tank fill tube may be damaged or incorrectly positioned, preventing the water level from reaching its proper level. Position the fill tube so water is flowing into the overflow tube (the open pipe near the center of the tank). If this doesn't fix the problem, replace the fill tube.
It's usually above the main bathroom. Inspect the opening and pull out any debris you find there. Birds and small animals are known to crawl into vents occasionally. They can create enough of an obstacle to block air flow.
There are many causes for a slow flushing toilet—your tank may have a low water level, a toilet or pipe clog or calcium and hard mineral buildup.
This sound can happen intermittently and occur every few minutes or every few hours. Such a refill sound is usually alerting you that your toilet is losing water, either internally (if there's no water on the floor or exterior of toilet) or externally leaking if you see water outside the toilet.
Most professionals recommend spending no more time on the toilet than it takes to pass a stool. Studies have shown that the average bowel movement takes 12 seconds. Sometimes it does take longer, however, so at maximum, you should not spend more than 10 minutes on the toilet.