Your toilet is taken for granted, until it becomes a running toilet, potentially wasting thousands of gallons of water a month. As homeowners we sometime ignore the problem but it will not fix itself.
Sometimes the toilet is running because the flotation bulb, located in the tank, is not positioned properly. If you lift the rod attached to the bulb, and the water stops running then you can simply bend the rod slightly upward and that should solve the problem. The other thing that could be happening is that the bulb has a crack in it and has taken on water so it not functioning properly. If this is the case simply remove it, bring it to your handy hardware store, and they can replace it with an exact model.
Another reason for a running toilet would be a problem with the stopper and valve seat. They are both made of rubber and will disintegrate gradually over time, causing a less than perfect seal, causing a running toilet. If this is the case simply remove this unit and pay another visit to the handy hardware man and they will replace it for you. Before you do this, however, clean the stopper and valve, and that might be enough. Grime can build up on both affecting the seal.
If this does not appear to be the problem, then check the chain tension to the flapper. If it is too tight, then the flapper cannot close properly and you have a running toilet. The chain can also corrode over time which can affect its length. Sometimes they can double over on themselves and cause the same problem.
If it does turn out the flapper assembly is the issue, then you need to replace it. The process is very simple. First turn off the water supply to the tank, this shut off valve is located behind the toilet and towards the ground, turn it clockwise all the way. Next, flush the toilet so the tank empties and you can work. Unhook the chain from the old flapper valve and pull up the flapper, it will come up easily. At this point examine the chain as well. If it’s corroded or has kinks in this replace it as well. You can acquire these parts at your hardware store.
It’s a very simple matter to hook up the new flapper assembly, and also the chain if you have switched that out as well. You may need to fiddle with the chain to get it adjusted right initially. Now, of course, you can turn the water back on and test the toilet. This is the time when you can see if the chain needs to be adjusted additionally or not.