Of all the plumbing repairs around the house, fixing the commode is the one that typically gets done most quickly. If you are like us, you’ll agree that having a quiet, nonleaking commode is important enough to learn how to take care of problems when they first rear their ugly heads.

Repairing a leaky toilet

The toilet is the most common household water waster. A badly leaking toilet can waste nearly eighty thousand gallons of water a year. While repairing a leaky toilet is a major water conservation project, it is actually a very simple plumbing project. This diagram and the following instructions can help you understand the inner workings of your toilet and make adjustments as needed.

One of the most common toilet problems is excess overflow. This often happens because the water level in the tank is not balanced correctly. The water level should be a half inch or less below the overflow tube. When the water level in the tank rises above the overflow tube, the water will run into the toilet bowl constantly. When the level is too low, the toilet may not flush fully. Luckily, both problems are easily fixed with a screwdriver and a little know-how.

1. Determine the flushing mechanism. Most toilets have one of three different types of flushing mechanisms: a float arm, a float cup, or a metered fill valve. A float arm looks like a balloon on the end of a metal rod, the rod part being the “arm.” Usually, the float is made of black rubber, but it can be made of other materials as well. A float cup has the float part wrapped around the refill pipe rather than on the end of a metal arm. A metered fill valve is found on older commodes and does not use a float to control the water level in the tank.

2. Adjust the float arm, the float cup or the metered fill valve. 

• Float arm: Adjust the level of the float. If the arm is metal, you can bend it either up or down to raise or lower the float. On plastic arms and some metal arms, there will be a knob at the ball cock, where the arm meets the vertical pipe that supplies water back into the tank. Be sure that the float rests halfway in the water. If it is covered by water, the float has a leak in it and needs to be replaced.
• Float cup: A float cup has its float situated on the intake pipe instead of on the end of a metal arm. To adjust the level of a float cup, find the metal clip that holds the cup in place along the refill pipe and squeeze it. Move the cup to the desired level and release the clip.
• Metered fill valve: If you have a metered fill valve, we recommend upgrading the flushing mechanism to a float cup or float arm to help minimize problems. If that is not an option right now, take a flathead screwdriver and turn the screw found on the fill valve clockwise to raise the water level, counterclockwise to lower it.

3. Adjust the water level.  Check the level of water in the tank, which should be a half an inch or less below the overflow tube (see the picture). Adjust the water level up or down accordingly, and flush to check that the level is balanced, and roughly one-half inch below the top of the overflow tube. Repeat until you get it right.