Toilet runs off and on, what are the causes? It can be referred to the water system. As people know, the system of toilets has not changed much since it was first introduced. Do not be surprised if people often find the same problem even though it has been several years and even decades later like random flushing. First, identify the principle or mechanism of the toilet. Observe it, if necessary.
When the water does not stop flowing or stop by itself, open the tank and check. In addition, when the water cannot be filled, then the possibility is that the stopper cannot close. People can fix it by covering it by hand. Otherwise, look for the causes and fix it. It can be caused by a caught chain, wrong position or it is not parallel to the hole, and others.
Check also the water level. Make sure the water is on the recommended line. If the water supply is insufficient then this could be the cause of the toilet keeps running on. Check the water valve and its position. Then, adjust also the height of the float so the tank is not filled with too high water. Other component such as broken lever where it connects the plastic ball can also be the cause of problem in the water flow system.
If it happens, then people should replace it or use super glue for as temporary solution. These may not apply if someone has a toilet with a different or unusual system. Do not do it yourself if you do not know about the toilet system thoroughly.