A running toilet can waste hundreds of gallons of water per day while racking up your water bill. This a problem you’ll want to address quickly! The best way to fix a running toilet is to start by inspecting the toilet flapper for issues. Toilet flapper issues are one of the most common causes of a running toilet. If the toilet flapper seems fine, try adjusting the water level of your toilet. Finally, if your toilet is still running, you’ll probably need to replace the toilet fill valve.
Addressing Flapper Problems
1. Turn off the water and drain the toilet. Before you can check the flapper for problems, turn off the water to the toilet. Flush the toilet to drain excess water from the tank. This will allow you to inspect the flapper without having the toilet running constantly.
The flapper is a round rubber seal that stops water from draining from the tank and into the toilet bowl. When you flush the toilet, the chain pulls the flapper up so fresh water can fill the bowl.
Problems with the flapper are among the most common causes of a running toilet.
2. Remove the toilet tank lid and look inside. Lay down a towel somewhere safe and out of the way, such as in a corner. Hold either end of the lid firmly with both hands and pull the lid off the toilet. Place the lid on the towel to prevent it from getting scratched.
Toilet lids are made of heavy ceramic, so don’t place them anywhere they can easily be knocked over.
3. Adjust the chain length if necessary. The chain that pulls the flapper up can cause problems if it’s too long or too short. When the chain is too short, it will pull up on the valve when it shouldn’t, allowing water to drain constantly. When the chain is too long, it can get caught underneath the flapper and prevent a seal.
- If there's too much tension on the chain, remove the hook attaching the chain to the flush lever. Move the hook up 1 or 2 links until the chain has more slack. Reattach the hook to the flush lever.
- If the chain is so long that it can get caught under the valve, use a pair of wire cutters to trim a few links from the top of the chain. Reattach the hook to the new top link and reattach it to the flush lever.
4. Inspect the flapper for problems. Remove the flapper by unhooking the sides from the pins at the bottom of the overflow tube, which is the open tube in the center of the tank. Inspect the flapper for mineral deposits, warping, discoloration, disintegration, and other signs of trouble.
You can clean a dirty flapper that’s got mineral buildup on it.
A flapper that shows other wear-related problems should be replaced.
5. Clean a dirty flapper. Mineral deposits from the water can build up on the flapper and prevent it from sealing properly, allowing water to run. To clean the flapper, soak it in a bowl of vinegar for 30 minutes. After 30 minutes, scrub the rubber with an old toothbrush to dislodge buildup and dirt.
- Alternatively, put a few drops of baby shampoo on a rag and use it to wipe down the flapper. This will clean the flapper and add more elasticity to the rubber.
- When the flapper is clean, put it back in place. Attach the hooks on the side to the pins on the overflow tube.
- Turn the water back on and let the toilet tank fill.
- Listen for the sound of water running to see if that fixed the problem.
6. Replace a worn flapper. If the flapper is brittle and hard or doesn’t seal well after cleaning it, purchase a new one. Take the worn flapper to the hardware store and purchase a new flapper in the same style and with the same dimensions. You can also buy a universal flapper that will fit any kind of toilet.
- To attach the new flapper, fit in into place and attach the hooks on the side to the pins on the overflow tube.
- Turn the water back on and test the flapper to see that it’s functioning properly, and that the toilet isn't running.
Adjusting the Water Level
- With the water running and the tank full, look at the overflow tube. This is an open tube in the middle of the tank that connects the tank and the toilet bowl.
- Check to see if water keeps draining into the tube. If that’s happening, you can adjust the water level by lowering the float.
2 .Determine the type of float you're dealing with. Water comes into a toilet tank via a fill valve. The fill valve has a float on it that rises or lowers with the water level. The float height is what tells the fill valve to shut off when the tank is full. Therefore, you can lower the water level in the tank by adjusting the height of the float. There are 2 main types of floats:
- A float ball fill valve will have a long arm attached to the fill valve, and at the end of the arm there will be a rubber ball-shaped float.
- Shake the float ball to determine if there is water inside it. If so, replace it.
- A float cup fill valve will have a small circular cylinder wrapped around the body of the fill valve. The cylinder, or float cup, slides up and down on the fill valve shaft, and its height determines the water level.
- Flush the toilet and let the water in the tank refill. Check the water level.
- Ideally, the water level should be 1 to 1.5 inches (2.5 to 3.8 cm) below the top of the overflow tube. Continue adjusting the screw by quarter turns until the water level is right.
- Flush and refill the toilet tank.
- Check the water level.
- Make another quarter-turn adjustment if necessary until the water level in the tank is 1 to 1.5 inches (2.5 to 3.8 cm) below the top of the overflow tube.
- To correct a fill tube that dips into the water, simply trim enough of the tube so that it sits above the water line.
Replacing the Fill Valve
- Turn off the water to the toilet.
- Flush the toilet.
- Use a sponge to absorb remaining water from the tank. Soak the sponge, wring it out in the sink, and continue until there's no water left in the tank.
- You may need a pair of pliers to loosen the locknut.
- You may want to take the old assembly to the hardware store when you purchase the replacement. That way, you can be sure to get the right size and style fill valve for your toilet. Alternatively, you can purchase a universal fill valve.
- You can replace older ball float fill valves with more modern float cup style ones.
4. Install the new fill valve and connect the water. Insert the new fill valve into the same place in the tank. Fit the valve into the hole in the tank where the water supply line comes in. Hook up the water supply line. Tighten the nut in a clockwise direction to tighten it.
- Once the locknut has been hand tightened, use the pliers to turn the nut another quarter turn.
5. Attach the fill tube. Connect the fill tube to the water output nozzle at the top of the fill valve. Position the fill tube so it’s draining into the overflow tube. If there's a clip on the overflow tube, attach the fill tube to the clip to keep it in place.
6. Adjust the float. Check the manufacturer’s directions to determine the correct float height for the fill valve you purchased. Use a measuring tape to measure from the bottom of the tank, and adjust the fill valve to the right height by turning the adjustment screw.
7. Test the fill valve. Turn the water back on and let the toilet tank fill with water. Check the water level, make sure the fill tube isn't in the water, and listen that there isn't any water running. Adjust the float height if necessary. Test the toilet by flushing it and letting it fill up again.
Once the toilet has been fixed and is no longer running, carefully place the tank lid back on.