A toilet that keeps running is a problem you’ll want to address sooner rather than later. It can rack up your water bill by wasting hundreds of gallons of water a day.
But don’t call the plumber just yet; there are a few things you can try on your own. Here are the 3 most common causes of a running toilet and a few ways you can fix them.
- 1 The Flapper is Not Working
- 2 The Water Level is Too High
- 3 The Fill Valve is Broken
The Flapper is Not Working
Inside your toilet tank, there is a small rubber valve that prevents the water from draining by sealing the flush tube.
When you flush the toilet, the lever lifts the flush valve, allowing the water to drain. A worn-out flapper is the number one cause of a running toilet.
Shut off the water supply to the toilet so you can check the flapper for problems. The shut-off valve should be located behind the toilet tank, connected to the water supply line (it can be a hose or pipe).
Many older toilets do not have water supply lines with shut off valves. If that’s the case with yours, try turning off the main water supply to your home. After you shut off the water, flush the toilet.
Remove the Toilet Tank
But, before you do so, grab a towel and lay it somewhere where it won’t get in the way. Toilet lids are usually made of ceramic, so to prevent yours from getting scratched, place it on the towel.
Adjust the Chain Length
If the chain that pulls the flapper is too short or too long, it can also cause problems. It will pull up on the flapper if it’s too short, or it can get underneath the flapper if it’s too long.
Whatever the problem is, the fix is simple. If the chain is too short, remove its hook from the lever. To give the chain more slack, move the hook up 2 links or more if needed, but not too many as there should be enough tension for everything to work properly. Then, reattach the hook to the lever.
If the chain is so loose that it keeps getting caught under the flapper, remove the hook, and then remove a few links from the top of the chain using a wire cutter. Attach the hook back onto the chain and hook it to the lever.
Check the Flapper for Damage
You need to remove the flapper so you can properly inspect it. Pull the edges of the rubber valve from the mount pegs located on the overflow tube.
Clean the Flapper
If the flapper has mineral buildup on it, the mineral deposits may be preventing it from sealing properly. Clean it off, and then put it back in place. This may do the trick.
Replace the Flapper
If it’s worn out or damaged, it’s time to get a new flapper. There are various types of rubber valves, so it’s best to just purchase a universal flapper. You don’t need to waste time trying to find the perfect replacement.
But, you will need to make sure you get the right size. If the rubber valve in your toilet tank is the size of a grapefruit or a softball, you need a 3″ flapper. If it’s the size of an orange or baseball, you need a 2″ flapper. Flappers can also cause problems with the toilet tank not filling properly.
Once you get a new flapper, mount it on the pegs and hook the chain to it. To check whether this has solved the problem, turn the water back on and flush the toilet. If it’s still running, the water level in the tank may be the problem.
The Water Level is Too High
In every toilet tank, there is a tube that prevents the water from overflowing. The water will continuously drain down that tube when the water level is too high.
Adjust the Float
In the middle of the tank, you’ll find an open tube. Examine the overflow tube with the tank full, while the water is still running. If the water is continuously draining into the overflow tube, you need to lower the float.
The float is a device that lowers or rises with the water level. It’s attached to the fill valve. When the float reaches a certain height (when there’s enough water in the tank), it “tells” the valve to shut off the water. So, you can adjust the water level by adjusting the float.
Determine the Type of Float in Your Tank
There are two main types of floats. Your float is either a float cup fill valve or float ball fill valve.
Float cup fill valve: If there’s a tiny plastic cylinder wrapped around the fill valve, it’s a float cup fill valve. This type of float works by sliding up and down the fill valve shaft.
On top of the fill valve, you’ll find a screw. You can adjust the height of the float by turning this screw counterclockwise. A quarter turn should do it. To check whether it has worked, flush and refill the toilet tank.
The water level should be 1″ to 1.5″ below the opening of the overflow tube. If necessary, turn the screw a bit more.
Float ball fill valve: If you find a rubber ball floating in the tank, that’s a float ball fill valve. It should have a long arm that connects it to the fill valve. If there’s water inside the float ball, you will need to replace it. Universal float balls are easy to find.
Float ball fill valves are adjusted much in the same way as float cup fill valves. At the point where the float arm is attached to the fill valve, you’ll find an adjustment screw. To lower the float, turn the screw counterclockwise.
Flush the toilet and wait for the tank to fill. If necessary, continue adjusting the screw. If you can’t get the water level to be 1″ to 1.5″ below the opening of the overflow tube, the fill valve is most likely not working properly.
The Fill Valve is Broken
Generally, it’s a good idea to replace the fill valve about every 5 years as it wears out over time. You can install a universal fill valve, but the top of the fill valve should be set 3” above the top of the overflow tube, so it needs to be the right size.
Most universal valves allow you to adjust the height, but, if you don’t want to take any chances, you can simply bring your old fill valve to the hardware store to find the perfect replacement.
Disconnect the Water Supply Line
Like in step one, you need to completely shut off the water. Then, flush the tank and make sure it’s completely empty.
Before you disconnect the water supply hose, place a plastic container underneath it. You’d want to avoid making a mess if there’s some water left in the hose.
Grab a pair of pliers and unscrew the lock nut that secures the water supply hose to the underside of the toilet tank. Now you can safely disconnect the water supply line.
Remove the Fill Valve
On the underside of the tank, there’s another lock nut that holds the fill valve in place. Use an adjustable wrench to remove it. Then, you can remove the fill valve.
Install the New Fill Valve
The new valve should come with a shank washer, a cone washer, and a refill tube. With the beveled edge of the shank washer facing down, put the shank washer onto the bottom of the fill valve.
Then you can place the valve inside the tank. Place the cone washer onto the part of the fill valve that is sticking out outside the tank, where it connects to the water supply pipe. Each washer must create a water-tight seal around its connection point.
Now, you can tighten the lock nut. It’s best to do it by hand as you don’t want to tighten it too hard. You can easily crack the toilet tank if you tighten the lock nut with a wrench.
Attack the Refill Tube
Attach the new refill tube to the nozzle located at the top of the valve. Clip the other end of the refill tube to the overflow tube.
While making sure the washer is firmly in its place, connect the water supply hose to the fill valve. Turn the water back on and wait until the tank fills.
Adjust the Float
Check the instructions to see what’s the correct float height for your new valve. Turn the adjustment screw to adjust the float. When adjusting the height of the float, you can use a tape measure to make it easier.
Flush the Toilet
It’s time for the final test. Flush the toilet to see whether it worked. If there are no leaks, and the water is no longer running—congrats, you are done!
A running toilet is a real nuisance, but the fix is simple, takes no longer than 15 minutes, and anyone can do it.
If you are looking for a new toilet read our review of the best flushing toilets.