Why does the water periodically start running in one of my toilets?

ya you have a leak somewheres – we had a “phantom flusher” in my Grandpa’s house for the longest time. its because of a small leak and the floaty thing (love my terminology) has dipped enough to know you need more water in the bowl. Know any handy plumbers? It might be an easy fix.

Have you lifted up the porcelain lid and watched what the water intake, the guide rod and chain, and the rubber stopper do?

Here are some do-it-yourself tips and detection techniques.

http://www.doityourself.com/stry/repairtoilet

AllyMay is right, there is a floating device that will make the water start running when it gets low (it thinks it was flushed). So it will then fill back up to prepare for another flush. You have a leak somewhere, and you can tell how bad of a leak depending on the time between the water running and not running. Sounds like yours is somewhat small, since you can’t see it, and it takes about an hour or so for it to get low again.

If you wanted a quick fix during the night, you can use a rubber band or something to hold the floating device all the way to the top. Maybe then you can get some sleep. I’ve also used a 20oz coke bottle underneath the floating device to hold it up. That will prevent the water from running during the night, but by time you go to use the toilet, you will need to remove your temporary fix.

If you have a landlord I’d give him a call for a non-emergency repair, and they should get to it when they can.

Lurve for the 20-oz. Coke bottle.
Very engineering-based.

You can also buy (and have the landlord pay for) a little kit
to replace the floaty thing and its little bits of metal. The landlord would probably agree
to let you try that first; it would save him a trip. These are the toilet’s moving parts. They get cranky after a period of years. If that doesn’t work, you do need a plumber to see where else in the system something is leaking (presumably into the drain) enough to lower the tank water and cause the water to flow again.

Ah, yes…it’s just as I feared- a probable leak. Thanks for the link to do-it-yourself toilet repair and the coke bottle idea. I am my own landlord, I’m afraid, so I’ll be looking into the matter promptly so that the whining tennant (me) can get a full nights’ sleep and not suffer from a heftier than usual water bill.

You probably need to replace the rubber flapper at the bottom of the tank. As the flapper gets older the seal wears out and water slowly leaks into the bowl. This will cause the float to drop and the tank to refill. Everyone had some great ideas and tweaks, but they are only treating the symptom.
To fix:
Turn off the water to your toilet and flush it to empty the bowl. Remove the top of your tank and take a good look at the flap at the bottom. There will be a chain attaching the stopper to the handle. Disconnect the flapper and take it to a hardware store. Have one the helpful hardware people help you pick out a matching stopper. They should run about $5 – $15. Return home, clean off the drain where the stopper sits, install the new flapper, and your phantom re-fills should stop.
Also, you could try just cleaning the spot where the flapper sits before replacing it. This could solve the leak without a trip to the hardware store.

i cannot believe how timely this question and answer session is. we also have the “phantom flusher” and i figured it had to do with the ball or the flapper, so since i kinda know what the problem is, i haven’t fixed it just yet.

but my wife, on the other hand, will lose hours of sleep or even move to another bed as she anticipates “that sound.” see my question a few days ago on “WHAT ARE YOU PARANOID ABOUT?”

the phantom flusher in our house was part of the inspiration for that question.

@Charliecompany34: I totally know where your wife is coming from!

Unfortunately, the idiots who designed my bathroom installed the countertop directly over the tank lid, so I only have about 4” to snake my arm in and can’t peek in well enough to see what I’m doing. When i bought the house, this bathroom was going to be the second or third thing that was reonnovated, but seeing that it’s lost almost $200,000 in value in less than two years, the fixer-upper hasn’t been fixed up. Grrrrr…

You probably have a leaky flapper. Easy to change and they only cost a few dollars. You can find details at http:www.womens-home-repair.com.