Toilet Running Continuously
If your toilet is filling occasionally without flushing then you need a new flapper valve. The flapper valve is located at the bottom of the tank and is connected to the flush handle and rod with a chain. The flapper valve should sit flush in its seat and the chain should be left slack to allow for a proper seal. To change the flapper valve turn off the water to the toilet tank and flush the toilet to empty the tank. Unhook the chain from the flush handle rod. Once that is done, unhook the flapper valve from where it is attached to the base of the flush valve. To install your new flapper attach to the base of flush valve and reattach the chain to the flush handle rod.
If you have a constant trickle of water make sure the water isn’t running into the overflow tube. If it is running into the overflow that means your fill valve needs adjustment. To lower the float height, turn the adjustment screw or bolt at the top of the fill valve until the water level is at least an inch below the top of the overflow tube.
One other cause may be the float arm itself. If you pull up on the float ball and the water stops running then you need to correct the float height. Turn the adjustment screw or bolt at the top of the fill valve until the water stops flowing.
When looking for parts, it’s best to get the toilet brand name and date stamp. The brand name is almost always stamped on the bowl of the toilet, but it can also be found stamped on the inside of the tank along with the date stamp. This will help you find the correct parts for your toilet with little to no guesswork.