If your toilet isn’t flushing, the issue is likely with the upper tank because the bowl doesn’t have any moving parts, while the upper tank has two valves and a handle. Most repairs involve the upper tank, and can even be fixed through DIY methods.

How The Toilet Tank Works

The toilet tank holds a certain amount of water until the toilet is flushed, at which time the water in the tank rushes down through an opening in the bottom of the tank and into the bowl, forcing waste into the drain and sewer lines.

The toilet fill valve fills the tank with water and is also known as the ballcock or refill valve. The four different variations of the fill valve are plunger-type ballcock, diaphragm-type ballcock, float cup fill valve, and floatless fill valve.

Replace a ballcock

To replace a ballcock, bend the float arm downward and the float ball will shut off the water at a lower tank level. This may be necessary if the toilet is running non-stop after a flush cycle has been completed. If this doesn’t help, you may need to replace the ballcock with a modern float-cup style fill valve.

Repair the flush valve

The flush valve is located in the center of the tank and has a plastic or brass fitting attached to the bottom opening on the tank. To repair the flush valve, turn off the water supply to the tank and remove the old flapper. Then, remove the remaining tank water and clean the valve seat. Install the sealant ring and position the flapper assembly at about a 45 degree angle to the front of the tank. Attach the lift chain, turn on the water, and fill the tank.

Fix a running toilet

A running toilet typically occurs because the flapper isn’t seated correctly in the opening of the flush valve, or because the water level in the tank is too high.

Solve a loose flush handle

A loose flush handle can be fixed by reconnecting the lift wire or lift chain that attaches the lift arm from the flapper. Or, you may need to adjust the handle mounting nut inside the tank.

Unclog a toilet

A toilet clog can be fixed with a specialized toilet plunger or a toilet auger.