How to Fix a Free-Flowing Toilet

How Your Toilet Works

Before starting any repairs, you need a basic understanding of the parts in your toilet tank and how they work together.

• When you press the flush handle or button, a chain lifts a flap, known as a flapper, which allows water to flow from the tank into the toilet bowl.
• A plastic float sits on top of the water and drops down as the tank empties. This float is connected to a fill valve that opens when the float is down and closes when it’s up.

In the center of the tank is an overflow tube which drains excess water into the toilet bowl if the level in the tank gets too high.

Identifying the Problem

A few different things can cause a toilet that continually runs. Most commonly it stems from a faulty flapper. But it could also be due to the high water level in the tank, a water-logged float, or a broken valve. Each issue is easily fixable and the parts available from most hardware or household goods stores. You just have to know which part is causing the free-flowing water. To identify the problem, gently lift the lid off the tank and place it safely out of the way.

Switch off the Water

Before attempting to solve your running toilet issue, you need to empty the tank of water. To do this, you must first close off the water supply to the toilet. Look for the water supply pipe going into the tank, usually located on the bottom left-hand side. Follow the pipe to where it disappears into the wall or floor. Somewhere along the pipe, you will see a tap, which is the shutoff valve. Turn off the tap in a clockwise direction until it’s closed.

Flush the Toilet

Now that there’s no water going into the tank, flush the toilet. Hold down the flush lever or button until the tank is as empty as possible. You might find there is still a small amount of water left at the bottom of the tank. If so, use a large, absorbent sponge to soak it up.

Check the Flapper

A Flapper can become dirty, brittle, or warped, meaning it no longer creates a proper seal and allows water to run freely into the toilet bowl. To remove the flapper, unhook the sides from pins at the base of the overflow tube. If there are mineral deposits or dirt on the flapper, place it in vinegar for 30 minutes before brushing off any dirt with an old toothbrush. If your flapper’s showing signs of wear and tear, you will need to buy a new one. Take the old one to the store to ensure you get one in the same style and follow the instructions on the package to install it.

Adjust the Chain

If the chain is too long, it can hang down and become caught beneath the flapper. Trim off any excess to prevent this from happening. When the chain is too short, it will pull up on the flipper when it shouldn’t causing water to constantly flow. Move the chain’s hook down a couple of links until it’s at the right length. Some modern toilets may have a grooved piece of plastic instead of a chain. In the same way, move the float down a groove or two to shorten the length.

Adjust the Water Level

If the chain and floater both seem to be functioning but your toilet is still free-flowing, it’s time to check the water level. If the level is too high, water will always be draining into the overflow tube and into the toilet bowl. Turn on the water and wait for the tank to fill. Keep watching to see if water drains into the overflow. If so, you need to lower the float by adjusting the screw at the place where the float arm adjoins the fill valve. Using a screwdriver, loosen the screw a quarter-turn counterclockwise. Flush and check the water level again. It should be 1-1.5 inches below the top of the overflow. Continue turning quarter turns until the level is right.

A Water-clogged Float?

When the float contains water, it will sit too low in the water. This will cause the fill valve to remain open and continually let water into the tank. Remove the float by unclipping or unscrewing it and give it a shake. If you hear water inside, replace it with a new one.

A Leaky Fill Valve

If the flapper, chain, and float are all working properly, and the water level is correct, the problem is likely to be the fill valve. Because they are cheap to buy, it makes more sense to replace the valve rather than attempt to repair it. Again, take the old part to the store to make sure you get the same kind to fit your toilet.

Replacing the Fill Valve

With an empty tank, disconnect the water supply pipe with pliers. You can now remove the fill valve by unscrewing the locknut and lifting it out. Follow the instructions for the new fill valve by inserting it into the tank and securing it with the locknut. Tighten the nut as much as possible by hand and then use pliers to turn the locknut a further half-turn. Take the hose on top of the fill valve and clip it onto the overflow tube. Reattach the water supply pipe and switch the water back on at the shutoff valve. Make any water level adjustments, replace the tank lid, and you’re done! By following these few simple steps, your toilet should no longer free-flow. However, if replacing the fill valve has not solved the problem, then it’s probably time to call in an expert!