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How to Fix a Running Toilet

What To Do When Your Toilet Keeps Running

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A running toilet can be one of the most annoying plumbing problems homeowners face. Jiggling the handle seems to be the universal tip, but that’s only a temporary fix until someone flushes the toilet again. Not only is a running toilet a nuisance, if the toilet keeps running it will waste a great deal of water and you’ll be paying a higher water bill. In fact, a “running” toilet is a leaking toilet that can waste up to 200 gallons a day or 6000 gallons of fresh water a month! This guide is meant to show you how to stop a toilet from running.

Step 1: Check the Water Level

Check the water levelThe first thing to do is determine if you have a leak and how much it is leaking. If the toilet is constantly running then you most definitely have a leak, but the fact is that most toilet leaks are silent. To check for leaks, you have two simple options. First, open the toilet tank and use a pencil to draw a line at the water level, then turn off the water supply valve beneath the toilet. Come back in an hour and see if the water level has dropped below your line.

The second way to check for a toilet leak is to squirt five or six drops of brightly colored food coloring into the tank. Wait 30 minutes to an hour and check to see if the water in the bowl has turned the color of the food coloring. If it has, you have a leak.

Step 2: Check the Flapper

Check the flapperNext, check the flapper valve in your toilet tank. The flapper is the rubber piece that flips open when the flush handle is used. It slowly lowers back down over the flush valve to close off the flow of water into the bowl. Reach into the water (it’s clean) and feel the flapper. The It should be soft and pliable. Over time, a flapper will get stiff and brittle and it will no longer provide a good seal against the mouth of the flush valve.

In most cases, replacing the flapper is how to stop a toilet from running. It’s important to inspect the chain that connects the flapper to the flush handle arm. If it’s too long, the chain may fall between the flapper and fill valve, allowing water to constantly drain into the bowl. If the chain is too short, it may prevent the flapper from closing fully and prevent the flapper from making a good seal when closed. Watch our video to learn how to change a flapper.

Step 3: Check the Fill Valve & Float Ball

The fill valve is the tall piece that connects to the toilet’s water supply line. You’ll notice that the top part of the fill valve is connected to the float arm and it has a float adjustment screw at the very top. When the toilet is running, lift the float ball and see if the running stops. Then look to see if the water level in the tank is high enough that it is allowing water to spill into the overflow tube part of the flush valve. If so, this is probably the main source of your leak and why your toilet is running. Adjust the float adjust screw and adjust the float to control the water level. You’ll notice the float attaches to a threaded rod. Turn it several times in one direction or the other to make the float sit lower or higher in the water. Ideally, the water level in the tank should be an inch or two below the top of the overflow tube.

Next, take a good look at the fill valve. Is water leaking out of the top? If so, it’s time to replace it. Plastic tank parts wear out over time, especially if you have hard water or use in-tank toilet bowl sanitizers.

Check the fill valve and float ball

Step 4: Check the Flush Valve

Check the flush valveIf you’ve replaced the flapper, adjusted the fill valve and float ball but you’re still trying to figure out how to stop a toilet from running, proceed to this step. The most likely cause is a leaking flush valve. Usually such a leak is around the mouth of the flush valve where the flapper is supposed to make a good seal. Lift the flapper and run your finger around the edge of the opening where water spills through the flush valve and into the bowl. Check for burrs, uneven, our rough areas. If you find any, you may be able to even them out with some emery cloth or fine grit sandpaper. The goal being to make a smooth surface for the flapper to seal against. If that doesn’t work, we suggest replacing the flush valve. It’s possible that age and in-tank detergents have deformed the plastic. This will require you to turn off the water to the toilet and drain the water to the bottom of the tank, then soak up the rest with a towel to empty completely.

There’s no substitute for a professional touch.

None of these problems is too concerning, as flapper and fill valves should be replaced every few years, regardless of whether you suspect a leak. In some cases, the problem isn’t related to the parts in your toilet tank at all and could be high water pressure causing your toilet to run. If your toilet was built before 1994, it probably uses more than 1.6 gallons per flush and you should consider replacing it with an efficient, modern toilet.

While toilets aren't complicated fixtures, it's important that all repairs and replacements are done right. If you're not the DIY type, or just want expert help, contact your local Roto-Rooter today.



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