How to Stop a Running Toilet
Shut the Water Off
Find the valve (looks like a hose) connected from your toilet to the ground. There will be a handle that you can turn. Turn it a quarter of a full turn to shut it off. You will be turning the valve handle that is closer to the ground – not the one connected to the toilet.
Removing the Valve
Remove the lid and put it somewhere safe- where it will not get damaged. Place a towel on the ground by the valve. Then, you will turn the other connecting line to remove the valve from the toilet. Water will exit from the fill valve so if you’d like a bucket to dump it into just grab one before you begin.
Check the Flapper
Now it’s time to inspect the issues. The problem will likely be either the flapper or the fill valve. You’ll start with the flapper (usually red or white) that is like a flat round rubber piece connected to a chain.
It’s important that the rim is intact and not cracked or damaged. If it’s damaged- time to run to the hardware store to change it out. (Find our directions on that here). Sometimes there is just debris around the rubber keeping it from closing all the way. Clean the debris out from around the rubber and see if that solves the issues.
Check the Fill Valve
If that doesn’t work, go to the fill valve. First, you will disconnect it at the top. There are two pieces clipped together on the side between the fill valve and the flapper. The lower part that is connected slides up and down the valve.
The top part is connected to the cap on the valve. Remove the cap at the top of the fill valve. This is the diaphragm valve; you will want to pull it apart and you will see a screw and a pin. If there is debris inside, rinse it out thoroughly under running water (If you see any debris inside the valve once the cap is removed, reconnect the valve on the lower side of the toilet so that you can flush that debris out).
Once the cap is clean, carefully put it back together and make sure you line up the pin correctly. Then take the cap back to the fill valve, turn and lock it into place.
Replacing the Fill Valve
First, get a wrench and remove the nut on the bottom (outside) of the toilet. You’ll want a towel under there (or a bucket) as water will exit. Take the fill valve out from the inside of the toilet. Take your new fill valve and measure it to the same length as the old one (if that length had been working up until this point).
Make sure there is a rubber washer where you will be sliding it into the hole of the toilet. Take the nut and screw it together. Tighten it with a wrench to make it snug. Make sure the part that slides goes high enough for the water line.
Put it Back Together
Reconnect the outside valve (the one that looks like a hose). Turn the water back on just a quarter of a turn. It will fill the tank in the toilet and watch it until it fills to the appropriate water level.