The three usual suspects
A running toilet almost always comes down to one of three things, and you can often tell which by looking in the tank.
- •1. The flapper isn't seating — water leaks from tank to bowl. Look for a worn or warped rubber flap at the bottom.
- •2. The fill valve isn't shutting off — water keeps filling past the overflow tube. The float's set wrong or the valve's shot.
- •3. The overflow tube's too high or the chain's too tight — the flapper lifts and won't close.
Which one to fix first
The flapper is the cheapest, most common cause, and the easiest to try. If a new flapper doesn't stop it, the fill valve is next. If the water level's right and both parts are new and it still runs, the flush valve seat itself may be corroded — that's a bigger job.
When to call
If you've tried a flapper and it's still running, or if the toilet's old enough that the internals are all original, call. A rebuild kit is a short job and it stops the waste. Describe what you see in the tank and I'll tell you which part it is.
Have a plumbing issue right now?
Call and leave a voicemail — Bob calls back during business hours. For the fastest reply (usually within the hour), email him directly.