Now you ask, but how do I know if it is the toilet that is running. The best way to figure this out is straight from the horses mouth so to speak. Go to the toilet in question and lift the cover for the tank off. The tank, in case you are wondering is, the big rectangular part that sits higher than the rest of the toilet. It is often where you will find magazines, crossword puzzles or decorative soaps. When removing the tank cover be careful, as it is often made of porcelain which can break if it is dropped. Also in this case it may be wet and somewhat slippery if water is splashing.
Once the tank cover is off you will know right away if your toilet is running as you should see a pump inside the tank working to fill the tank. You ask, why has it not overflown? Well, inside you will also see what looks like a somewhat rigid balloon. This is called the float, which when it drops below a certain point the pump will start filling the tank, and when it reaches a higher point, it will signal the toilet to stop. If your toilet is running, it most likely means that water is flowing out of the tank, which will keep the float from getting high enough to tell the pump to stop working.
The most common reasons that water is flowing from your toilet would be because of an obstruction of the flapper. The flapper is located on the bottom of the tank and looks like a little door. From it there should be a chain that connects back to the flush handle. Check around the flapper to make sure that there is nothing obstructing it or keeping it from closing all the way. It could be that a piece of debris has landed itself right in the way. It could also be that your chain for the toilet is too long and is getting caught underneath the flapper, this is something to watch for especially if the problem is intermittent. If you try to shorten the chain, make sure that it stays long enough to allow the flapper to fully close, it does not make sense to fix one problem and replace it with another.
Now, if you’ve gone through all this and you are still having problems there could be a problem with the internal workings of the toilet. If that is the case you can go to a local hardware store as they often have kits that contain the entire inner workings of toilets and replace them. You could also call a licensed plumber to come in and repair it if you are unsure of taking on the task of swapping out the internal workings.
A few things to consider, while the flapper system is the most common type of toilets, there are some that are done very differently. If that is the case it is often best to just replace the inner workings as it is usually more than just an obstruction. Finally, you could also try bending very slightly the arm that the float is on, as it could be that the water level is trying to go past the internal overflow drain. If you do this be careful not to adjust the float too much, or your tank will not fill with enough water.
My 50+ yr old toilet is ‘phantom flushing’ for 15 seconds every 15 minutes. The flapper has good seal, the float/fill mechanism is new. When I look down into the overflow tube, I can see the water ‘jiggling’. When I drop food coloring into the overflow tube, it immediately enters the bowl. There is no sign of leaking/wetness on the floor surrounding the toilet or anywhere else in the bathroom….3 local plumbers are baffled….got anything?
Hi JD,
I’m surprised that the 3 local plumbers haven’t solved this by now, hopefully you have more to pick from.
Here is a link to an article which lists the most common problems which result in a Ghost Flush http://411plumb.com/why-does-my-toilet-keep-running
Once these checks have been done the remaining repair that I would go with is replacing the entire flush valve.
Something you may consider is your old toilet flushes with about 5.5 gallons of water each flush.
Replacing it with a new one could save about 32,000 gallons of water per year with an average 3.2 person family size. http://411plumb.com/how-to-select-a-new-toilet-for-your-bathroom
I hope this helps you out,
Redwood