Worn Out or Warped Flapper: Over time, the rubber material of the flapper can deteriorate, become brittle, or warp. This wear and tear can prevent the flapper from creating a proper seal, allowing water to leak continuously into the bowl.
Sometimes when you put on a new one, it doesn't seat right. All it takes is a little build up of calcium on the opening and the flapper wont seat allowing water to leak under it. As the other person said, also check the chain length and the rubber ``ears'' on the flapper for any obstruction.
If the toilet doesn't flush completely unless you hold the handle down for the entire flush cycle, it's usually because the flapper is not fully lifting away from the flush valve. This problem is caused by too much slack in the lifting chain that connects the flush lever to the flapper.
Moving a float (a float is placed on the flapper chain) up the chain, so you are setting the flapper to close faster. By lowering the float on the chain you are causing the flapper to stay open longer.
Flappers can begin to fail from age, through mildew or mold, or through the growth of bacteria. These factors can cause the flapper to crack or to no longer fit perfectly around the flush valve. Some drop-in bowl cleaners are also hard on the rubber component of a flapper. As the flapper deteriorates it allows leakage.
Sign 1: Constantly Running Toilet
The flush valve acts as a gatekeeper, controlling the water flow from the tank to the toilet bowl when you flush. However, if the valve is faulty, it can cause the toilet to keep running, as it's unable to properly close and stop the water flow.
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.
But there's hope for our poor little flapper in the form of Vaseline, which can partially restore its youth and suppleness. Drain the toilet tank. Dry off the toilet flapper. Rub Vaseline on the flapper and its connecting washer until they soften.
The common solution is to replace the flapper that seals the flush valve opening, a job made much easier with a repair kit. A repair kit includes not only a new flapper but also drain seat insert and a sealant ring that fits over the existing flush valve opening.
Toilet flappers usually last for about 3 to 5 years, but the lifespan can vary depending on factors such as the quality of the flapper, the water quality, and the frequency of use.
If you've replaced the flapper and adjusted the float ball, but the toilet continues to run, the most likely cause is a leaking flush valve. Usually, such a leak is around the mouth of the flush valve where the flapper is supposed to make a good seal.
A worn fill valve means the seal is not entirely secure, and water can leak through. Water pressure. If your water pressure is too high, the water quickly passing through the narrow supply line to your toilet can cause vibrations or what may sound like a hissing noise.
The flapper, over time, can become loose or damaged, and it will need to be replaced. The total average cost of this repair is also between $70 and $200.
Common Signs Your Toilet Flapper Needs Replacement
If you hear the water running continuously in the toilet tank or if it takes too long to fill, you probably need to replace the flapper or the flush valve. Another sign that it's time for flasher replacement is when the toilet flushes on its own occasionally.
Drop about 4 to 5 food coloring drops in the toilet tank. You may want to use a dark color such as blue or red. Wait 20 to 30 minutes and then survey the toilet bowl. If the colored water appears in the bowl within 15 minutes, there is a leak in the flapper valve.
Check that the flapper is correctly aligned with the flush valve seat. Ensure the flapper's ears or pegs are securely attached to the overflow tube or flush valve. Verify that the flapper moves freely and sits flat against the valve seat when closed.
Gently lift the flapper and scrub it with an old toothbrush or scouring pad. Scrub the seat assembly as well. Turn the water back on and test your work. If cleaning doesn't fix the leak or the flapper is physically damaged, you need to replace it.
The Toilet Is Constantly Running
If it's not sealing the flush valve opening, water from the tank will leak into the bowl, and the toilet will run constantly to keep the tank filled.
Ghost flushing, or phantom flushing, occurs when your toilet tank refills independently without anyone pressing the handle. Water leaks from the tank into the bowl, causing the fill valve to activate periodically to refill the tank. It's similar to your toilet flushing itself, but it's just refilling.
Debris that builds up over time inside the water system, including the valve body, supply line or shut off valve (at the wall) can restrict the flow path of water and slow down the valves filling speed. Toilet fill valves in use for a period of 7 years or more can have their working parts start to wear out.