A toilet that runs continuously or turns on and off even when not in use has a leak somewhere. Most toilets are gravity-flow devices, with a tank that holds water and a bowl that is emptied when flushed and refilled from the tank. A float or fill valve controls the level of water in the tank and shuts off the supply when the tank is full. If this device fails, the water won't shut off or will start running again when the water level drops from a leak. Finding the leak is the key to the repair.
Put a few drops of food coloring into the reservoir tank and wait without flushing until the water turns on again. Check the floor around base of the toilet for water; colored water at the base indicates a problem with the seat that secures the toilet on the floor. Call a plumber to reseat the toilet unless you want to try removing the bolts holding it, lifting the tank up and installing a new seal and seat.
Look for colored water in the toilet bowl if water turns off and on; that will indicate a leaking flapper, the rubber seal that opens to drain water from the reservoir into the bowl. Shut off the water at the cut-off valve under the tank and empty the tank of water by flushing repeatedly. Disconnect the old flapper from the chain linking it to the flush handle, pull it off the overflow pipe and replace it with a new flapper; get the same style as the old one.
Lift the top off the tank when the water starts to run without the flush handle being moved and raise the ball float or arm on the refill valve; if that stops the water, the float or valve is defective. Replace a float, an older style of refill control, by unscrewing its arm from the water supply inlet and screwing a new one in place. Change a flush-and-fill valve by removing the old one where it is fastened to the bottom of the tank and installing a new one; follow directions that come with the replacement and are specific on steps to take. Use slip-joint pliers to loosen the connecting collars holding the valve.
Check the shut-off valve under the tank for signs of colored water or drips on the floor. Replace a leaking shut-off valve by turning off the water at the meter and draining the tank. Hold the main part of the shut-off with one wrench and use a second wrench to disconnect the water supply lines on both sides. Wrap the threads of a new shut-off with Teflon tape and secure it with nuts on the water supply lines on both sides.
Things You Will Need
- Food coloring
- Replacement flapper
- Replacement ball float or fill valve
- Slip-joint pliers
- Replacement shut-off valve
- Drain a toilet tank by shutting off the water at the cut-off valve and flushing it repeatedly. Have a bucket and a supply of towels handy to catch or sponge up any remaining water; it is impossible to completely drain a toilet tank.
- Consider replacing a float ball valve with a modern flush-and-fill type if the float ball is defective. Modern valves are more reliable and are easy to install following step-by-step directions with the valve,
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