If the water in your toilet is running intermittently or if it sounds like the water in your toilet won’t stop running, then the most obvious cause is almost always the toilet flapper. I had this happen to me recently and thought I’d explain how I fixed it.
The more a toilet runs when it’s not flushing, the more you are wasting water and racking up your water bill. Replacing that cheap toilet flapper is a simple DIY plumbing project that could save hundreds of dollars in water bills over the years.
My old toilet flapper. The curled and worn lip seal around the flapper edge was leaking and causing my toilet to run intermittently.
The toilet flapper is that little rubber gasket at the bottom of your toilet tank that is attached to one end of the chain or lever which extends up to most toilet handles. It helps if you understand how a toilet works. Most standard American toilets are pretty straight-forward devices: they have a tank which holds water and a bowl with some odd bends in the pipes beneath it. The toilet flapper sits between the tank and the boil. A toilet works with the help of gravity. When flushed the water from the tank pushes into the bowl with enough force to push everything through the bends of the pipes under the bowls.
That’s why toilet tanks are almost always above the bowl: they need gravity to work. The tank behind the bowl can then fill up with water again. Even if you have low water pressure, the toilet tank will eventually fill and you’ll have enough water in the tank to once again flush everything down with force.
The toilet flapper essentially serves as a sort of “trap door” that keeps the water in the toilet tank and then opens and releases all that water when the toilet is flushed. The flap door (toilet flapper) then closes shut again, allowing your toilet tank to once again fill with water.
If your toilet is constantly running, or even intermittently running, without you flushing it, then you have a leak somewhere. Water leaks are never good news, but some are more dangerous than others. Toilet bowls can crack, seals can break and water can leak. If your toilet is cracked or if you see any sort of structural damage to the bowl or tank of your toilet you’re most likely going to have to remove the toilet and replace it with a new one. That being said, most toilet problems do not require anything so drastic. Most toilet leaks occur in or around the flushing mechanism of the toilet, and that’s easily fixed. So let’s find that leak!
First look around the wall and floor area of your toilet, looking for any soft spots, puddles, or water damage. If you see any you have some serious problems and will probably need to replace the toilet and fix some water damage. If you don’t see any water leaking outside the toilet, the leak is most likely inside the toilet.
So how do you fix a running toilet with a leak inside it? You fix the leak, and the flapper is the first place to start. Toilet flappers are usually made out of rubber or soft plastic and are designed to “seal” the hole at the bottom of your toilet by having the weight of the water above them “push” them tight. This works great when the toilet flapper has a snug fit, but because most of these flappers are made out of soft material for sealing, they are also prone to wearing down and dry-rotting or degrading over time. Toilet additives like those bleach tablets can hasten damage and wear on a flapper. When the toilet flapper begins to wear out little streams of water will slowly leak into the bowl, decreasing the water in your toilet tank until it triggers the weight mechanism in your tank to run more water to keep it full.
You can test to see if your flapper is leaking or not fairly easily: put some non-staining colored liquid in your toilet tank and wait to see it start running. When it runs, see if you can see the colored liquid in the bowl below. If you do, then it’s definitely your toilet flapper that’s leaking. You can pick up some cheap toilet leak dye online or at a hardware store or you can just use your own colored liquid (make sure it won’t stain the toilet!) My favorite colored liquid of choice? A few cups of old coffee. Pour enough in the tank to make it nice and dark and wait to see any leaks. Flush the toilet fully just so the tank can refill with clean water once you’ve determined that the flapper is leaking.
If something else is leaking on or around your toilet you may need to take more drastic measures. If you begin to see leaks from your toilet tank or toilet bowl (or you find any cracks in the porcelain) then you might want to simply remove the old toilet and then replace it with a new one.
How To Fix A Leaky Toilet Flapper
Step 1 – Turn off the water supply line to the toilet. That’s usually a little silver knob or valve behind or under your toilet which controls the flow of water into your toilet. Once you think it is turned off, flush your toilet. If it flushes and the tank doesn’t refill, you found the right knob. If your toilet starts running and filling with water, then you might have to turn off the water somewhere else in the house. Alternatively, you could somehow “trick” your toilet into not running anymore by tying or propping up your toilet tank float, making it seem as though your toilet tank is full. Either way, flush your toilet and empty as much water as possible from your toilet as possible.
Step 2- Remove the water from the toilet bowl. I usually now use a plastic cup and I scoop the majority of the remaining water from the toilet tank and just dump it in the bowl. I’ve found that most toilet tanks still have some water in them after flushing. Try to get as much water out as possible so you can expose the toilet flapper. Yes, toilet water is usually very cold.
Step 3 – Examine your toilet’s flapper valve. If it’s worn or old or simply not sitting right, then you’ll have to replace it. If you happen to know your toilet brand then you can sometimes just buy an American Standard toilet flapper or a Kohler toilet flapper or a Gerber toilet flapper or even a Toto toilet flapper. My house was built around 1950 and my toilet is originally, so I have no idea what brand my toilet is. Even if you know your brand I’d recommend taking the flapper out and going down to your local hardware or home improvement store. It usually just pops off the valve seal at the bottom of the tank. You might want to take along the chain or rod that’s attached to the toilet flapper just to be sure.
Step 4 – Purchase a replacement toilet flapper. Go to the plumbing section of the home improvement store and you’ll find a whole wall of DIY plumbing and toilet repair items. Your best bet is to try to find a toilet flapper that the most closely resembles the toilet flapper you had. Pay special attention to the back or hinge portion of the toilet flapper because those have to match the seat at the bottom of your toilet tank. Other than the brand names, there are some general all-purpose toilet flappers that fit a variety of toilets. Toilet flappers usually cost less than $10, so fixing your constantly running toilet is a pretty cheap repair.
Step 5 – Install your new flapper in place of the old flapper. Attach the chain or lever and do some “dry flushes” a few times to make sure everything seems to be working. The toilet flapper may not automatically go down, but that’s okay because most are designed to work with a tank full of water above them, not just dry air.
Step 6 – Test your toilet flush mechanism and flapper. Once you’re satisfied that the toilet flapper is installed properly, turn on the water (or untie the toilet tank float) and let the tank fill with water. Cross your fingers and flush the toilet, but pay special attention to how the flapper works. Is it opening enough? Did a full tank of water get flushed out? Is it closing properly? You may need to adjust the chain or lever tension or length to make sure everything is working just right.
There you go! For a few dollars you can pretty easily replace the toilet flapper in a toilet that’s constantly running and wasting a lot of water. Your toilet should now only run when flushed thanks to that new toilet flapper.