Toilet keeps running

A toilet that keeps running, refills on its own or hisses is almost always one of four parts inside the tank. Lift the lid, flush once and watch. Our guide why your toilet keeps running walks through the EPA dye test for a leaking flapper.

• Refills by itself, or trickles into the bowl: the flapper leaks.
• Runs until you jiggle the handle: the chain or handle holds the flapper open.
• Water spills into the overflow tube: the water level is set too high.
• Hisses with the level set right: the fill valve is worn.

Every one of these is a beginner repair with the water shut off at the valve behind the toilet. The step-by-step videos are on Fix a running toilet. If water is on the floor around the base, see Replace a toilet instead.