How to Repair a Leaking Toilet A leaking toilet can be a real inconvenience, especially for those who only have one bathroom in their home. Even worse if it happens late at night or on a weekend or holidays when it is impossible to get a plumber to come out on short notice. 

If you have the right tools on hand or can readily pick them up at your local hardware store, you can fix the leak on your own. Fixing a leak, as well as toilet installation, do not require the help of a plumber.

Use the following guide on how to fix a leaking toilet.

How to Repair a Leaking Toilet: DIY

Items you will need:

  • Ballcock assembly
  • Flapper
  • Lip joint pliers

Step 1: The reason your toilet is leaking could be the ballcock’s inlet valve or the float. If the water has risen higher than the overflow when you peer inside the tank, this could be the case. The float will rise as the water rises, thus letting the inlet valve know that it is time for the water to stop flowing. If it is broken, it could cause the toilet to leak or overflow. Flush the toilet. As the water is rising, carefully lift the part that keeps the float in place to check if the inlet valve is damaged. If the water stops, the problem is with the float and not the inlet valve.

Step 2: Located at the top of the ballcock is the screw that you use to adjust the float level. This helps you to choose the level that the water will reach in the tank. The problem could be the float if the adjustment does not stop the water from going into the overflow tube. The float could either be too low or have holes, which will prevent it from tripping the inlet valve. If this is the case, you will need to replace the float and rod.

Step 3: If you have tried both steps 1 and 2 and the water has not stopped leaking, the ballcock could be the cause. It is better to replace the assembly on the whole rather than trying to repair only the ballcock. Turn off the water at the shut valve. Holding down the handle (and keeping it down), flush the toilet. This will remove the majority of the water from the toilet tank. Use a sponge to remove any remaining water from the bottom of the tank.

Step 4: Remove the supply line connecting the ballcock’s bottom (located in the tank’s base). Remove the nut that secures the ballcock on the toilet tank with slip-joint pliers. Carefully remove the assembly by pushing it from the bottom up. Place the new ballcock assembly. Underneath the tank, a new nut should be added and tightened using the slip on pliers (be sure not to make it too tight or it could cause the tank to break.) Reattach the water supply line and clip the new refill tube in its place inside the tank. At the shut-off valve, turn on the water.

Step 5: In the event that the water level is not rising as it should and there is still water going into the bowl, the leak could be located near the flapper. To see if this is, in fact, the case, turn off the water as above and watch to see if the water level decreases in the tank. After 15 minutes, if there is a noticeable decrease, the flapper chain could have a leak or be too tight. 

Step 6: You will need to drain the tank to replace the flapper. Make sure the water is off as in the above steps. Using a clean cloth, make sure that the seat of the flapper is free of dirt. Next, inspect it for splits or cracks. 

Inspect the flapper itself to ensure that it is not damaged and is fitted against the seat snugly. If it is indeed damaged, simply remove and replace it with a new one. Make sure to use the exact same flapper, as others will not work. Install the new flapper at the base of the overflow tube on the hinge.

If none of the above fixes repair your leaking toilet, do not hesitate to contact DrainCom. We will send a licensed plumber to your home to fix the leak.