How to Fix a Running Toilet

Your toilet flushes just fine, but it doesn't know when to quit. Perhaps it stops running and then starts up again suddenly. Either way, it's wasting a lot of water and making that noise that keeps you up at night. Fortunately, it's usually not difficult or expensive to repair a toilet if you know a bit about how they work.

Steps

1. Get to know what's in your toilet. Mechanisms vary, but they all work on the same principles. Flush a couple of times while you watch in the tank with the tank lid off and notice the process.

Inside the tank, left to right: valve and float, fill tube, overflow tube and flapper. Handle connects to lever and chain.

• When you push the handle, the chain lifts a flapper, letting a tankful of water fall through the opening in the bottom, into the bowl. As the water level drops, the flapper drops and closes the opening.
• A plastic float drops as the water drains. The float is connected to a valve that lets water into the tank when the float is down and stops (or should stop) when the float is up.
• In the middle, there's also an overflow tube that drains water out into the bowl if it gets too high.

2. Catch it in the act. If you've waited long enough after flushing and the toilet hasn't quit running, lift the tank lid and look in.

3. Close the flapper. If the tank is not full and it is not filling, chances are that the flapper is stuck open. Reach in and close it with your hand. If it sticks repeatedly, look for the cause. Make any necessary adjustments.

The lever, chain and flapper must all work together. Adjust them so they do not catch or tangle.

• Is the chain catching on something?
• Is the flapper catching on the chain?
• Is the flapper wedged open on its hinge?
• Is the flapper aligned with the opening?
• Is the flapper simply just old and stiff (and needs replacing)?