How to Fix a Constantly Running Toilet

Dear Home-Ec 101,
The toilet, in my bathroom is constantly making noise. It sounds like water is always running. Is there any way to turn that off?
For the Love of Pete, Someone Jiggle the Handle Already!

Heather says:

There are a few things that can go wrong inside the tank of a toilet that would cause it to leak and need to fill more often than it should.

Take a peek under and behind the toilet, if no water is present, the leak probably is occurring inside the tank. If there is water present, you may need to replace the plastic washers on the bolts securing the tank.

The inner workings of your toilet may need to be fixed or replaced. Don’t worry, this is a straightforward job. If you can put together Ikea shelves, you can handle this plumbing task. Before you go to the hardware store, see if you can turn off water at the inlet valve. Unfortunately some contractors are skipping this handy mechanism to save a few bucks and it may not exist in all homes. Look for a valve on the woven or copper pipe that connects to the bottom of the toilet tank. Turning this off prevents the tank from filling. If you don’t have an inlet valve between the water line and the tank, you may have to shut off the water at the main to fix the toilet. It’s kind of a pain, but better than making a huge mess.

If there is no water present, take the lid off of the tank and take a peek inside.

If your float has cracked

Older toilets have what looks like a metal or plastic balloon that rests on top of the water. Sometimes these floats can develop cracks or leaks that allow water to seep inside. When this happens the float no longer sits above the water, causing the mechanism to fill the tank higher than it should. If the float is resting too low in the water, the toilet can overfill high enough to leak into the overflow tube creating a vicious cycle of filling and draining. I say vicious because it’s murder on the water bill.

Sometimes the metal rod or arm of the float just needs to be bent slightly to get the float to sit properly on the water. Do this carefully, if the rod snaps, the water will need to be shut off.

If you have a newer toilet, the float rides up and down a plastic tube, like a little balloon elevator. Sometimes the float gets stuck on grit or debris and just needs to be moved manually a few times to get things working again. If the elevator style float has developed a leak, it will need to be replaced.

If the float is not the problem

It could be the chain attached to the handle. If the chain is too long, it may become trapped under the flap allowing water to slowly leak. If the chain is too short, it won’t allow the flap to seal properly. Shorten or replace the chain as necessary.

The flap may also be leaking.

If you look on the inside of the tank there is often a warning to not use products with bleach. Over time these drop-in cleaners degrade the plastic, causing it to become brittle and crack. If this has happened, the flap will need to be replaced.

Don’t worry

The internet is full of *ahem* helpful advice that may actually create problems.

If you live in the USA and your toilet is newer than 1994 it only uses 1.6 gallons per flush. The toilet needs all 1.6 gallons to flush properly, please do not add a brick or bottle to reduce the capacity of the tank.  Without enough water to flush waste, the toilet is more likely to clog. In older toilets the addition of a brick to the tank may introduce additional sediment to the trap. If you need to reduce the tank capacity, use a plastic bottle full of water and replace it on occasion as the plastic becomes brittle.


  1. Thankful on July 29, 2010 at 2:27 pm

    I'd replace all parts on the interior of the tank. Cost of massive house flooding due to broken tank-filling mechanism: $60K+. Cost to entirely replace tank-filling mechanism for one toilet: $29.95 plus tax at Home Depot. Thankfully, our insurance company was great with covering the loss, but it was a complete nightmare getting our house back in order and took almost 6 months, during which time all of our routines of cooking, cleaning, etc. were drastically disrupted. We were out of town at a wedding the weekend our toilet broke, and more than 16,000 (!) gallons of water flowed through the house — the tank-filling mechanism basically cracked at the base. Our insurance company and plumber both recommended replacing the tank-filling mechanism about every 5 years, and when we went to replace the inner tank workings on another toilet, the bolts holding it on basically crumbled at the site of a wrench. (If you'd like to see what kind of damage can result, check out my post with a few pictures:… It still makes me shudder to look at them.)

  2. mom, again on July 23, 2010 at 5:58 am

    another reason the toilet could be running constantly is that there is too much water pressure in your house. If you have more than one toilet running or sink dripping, there is a tester thing you can use to test to see if the pressure is what your water supplier says it ought to be. It might be worth borrowing or seeing if the water supplier will do this test before spending lots of time and money fiddling around with the bits in the house.

    You might also have a pressure regulation tank which might also be broken.

    We had both problems, and if we hadn't been too lazy to contemplate doing all the tinkering above, we would've wasted a lot of time and money at it. Instead we called in a plumber and he figured it right away. The only bits that needed replacement were those things in the garage we didn't know existed!

  3. asyhre on July 22, 2010 at 10:32 pm

    Also, if you live somewhere with a lot of junk in your water that can build up around that flappy seal thing and needs to be cleaned. Remember both the rubber flap and the plastic seal thing.

  4. margo on July 22, 2010 at 4:47 pm

    I live in an apartment that was designed to be shown as a model, but not for anyone to actually live in, I swear. The toilet is just one of the items that was not designed for real use. A plumber told me that the opening was not big enough to allow proper flow. But, since I rent, there is nothing I can do about it. I have finally figured out that the toilet needs just a little more water to do its job properly. So I try to conserve H2O in other areas so I can pour a little as needed into the tank to help it do its job. It's a pain, but it does not continuously run anymore!

  5. tastelikecrazy on July 22, 2010 at 4:29 pm

    Chamber pot. Sorry, couldn't help myself.

    I actually had a broken chain last week and used a industrial grade paper clip to splice the pieces together. 😀

  6. Janet Foster on July 22, 2010 at 2:33 pm

    We totally have this problem at my house. The chain gets stuck under the flap or gets tangled around the stem so it won't close completely. We have to stay on top of it all of the time. Home Depot has a great book on home repair and it goes through toilet fixes.

  7. imabug on July 22, 2010 at 2:31 pm

    I just had to replace the flapper valve in one of my toilets last week. There is an almost dizzying array of them at $homeimprovement_store. If you need to replace yours, either bring along the old one or figure out what size you need. I discovered there's a standard 2" one, and also one that fits larger 3" holes.

    There are also flapper valves that claim to be chlorine safe.

    • casey on July 22, 2010 at 5:58 pm

      I had to do that a couple months ago. I removed the old one, went to the store, found a guy wearing an orange apron and said "i need this". He got me the appropriate one, and even showed me how to install it on a display toilet.

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