How your toilet works

Two assemblies are concealed under the lid of a toilet tank; a ball cock assembly, which regulates the filling of he tank, and a flush valve assembly, which controls the flow of water from the tank to the bowl. When someone presses the flush handle, the trip lever raises the lift wires (or chain) connected to the tank stopper. As the stopper goes up, water rushes through the valve seat into the bowl via the flush passages. The water in the bowl yields to gravity and is siphoned out the trap.

Once the tank empties, the stopper drops into the flush valve seat. The float ball trips the ball cock assembly to let a new supply of water into the tank through the tank fill tube. As the tank water level rises, the float ball rises until it gets high enough to shut off the flow of water. If the water fails to shut off, the overflow tube carries water down into the bowl to prevent an overflow.

Troubleshooting Toilet Problems

Noisy Toilet

Check for:

• Restricted water flow.
• Defective ball cock assembly.

Remedies:

• Adjust the shutoff valve first.
• Oil the trip lever or replace the ball cock washers.
• Replace the entire ball cock assembly.
• CAUTION: First turn off the water at the fixture shutoff valve. Then flush the toilet to empty the tank and sponge out any remaining water.

Running Toilet

Check for:

• Float arm not rising high enough.
• Water-filled float ball.
• Tank stopper not seating properly.
• Corroded flush valve seal.
• Cracked overflow tube.
• Ball cock valve doesn't shut off.

Remedies:

• Bend float arm down or away from tank wall.
• Replace ball.
• Adjust stopper guide rod and lift wires or chain. Replace defective stopper.
• Scour valve seat or replace.
• Replace tube or install new flush valve assembly.
• Oil trip lever, replace faulty washers, or install new ball cock assembly.

Clogged Toilet

Check for:

• Blockage in drain.

Remedy:

• Remove blockage with plunger or closet auger.

Inadequate Flush

Check for:

• Faulty linkage between handle and trip lever.
• Tank stopper closes before tank empties.
• Leak between tank and bowl.
• Clogged flush passages.

Remedies:

• Tighten setscrew on handle linkage or replace handle.
• Adjust stopper guide rod and lift wires or chain.
• Tighten tank bolts or couplings or replace gasket.
• Clear obstructions from passages with wire.

Leaking Toilet

• To stop a leak between the tank and bowl of a bowl-mounted toilet tank, tighten the bolts in the tank, or remove them and replace their gaskets.
• To seal the connections on a wall-mounted tank, tighten the couplings on the pipe connecting the tank and bowl, or unscrew the couplings, remove the pipe, and replace the washers.
• If the bowl leaks around its base, you'll have to lift the bowl up and reseal it along the base.
• If you don 't want to do this job yourself, call in a professional plumber.

Sweating Tank

This problem occurs most often in the summer when cold water in the tank cools the porcelain, and warm, moist air encourages mildew, loosens floor tiles, and rots sub-flooring. An easy solution is to insulate the inside of the tank by draining it and then gluing a liner made of foam rubber pads to the inside walls. A more costly remedy, and one that's usually a job for a professional, is to install a tempering valve that mixes hot water with the cold water entering the tank.

Check for:

• Condensation.

Remedy:

• Install tank insulation or a tempering valve.

Professional Tips

• When loosening connections, avoid slipping with a wrench and cracking the fixture by dousing stubborn connections with penetrating oil.
• When trying to detect a tank leak, add food coloring to the tank water if you can't tell whether your toilet is leaking around the tank bolts or just sweating. Wait an hour; then touch the bolt tips and nuts under the tank with white tissue. If the tissue shows coloring, you have a leak; otherwise, it's condensation.