Toilet Keeps Running? Here's What It Is and How to Stop It
A running toilet is the most expensive small problem in a house. A worn flapper can pass two hundred gallons a day without making much noise, and you only find out when the bill arrives.
Check the flapper first
Take the tank lid off and drop a little food colouring into the tank. Do not flush. Wait fifteen minutes and look in the bowl. Colour in the bowl means water is passing the flapper, and the flapper is the fix.
Flappers harden and warp, especially in hard water areas. They are inexpensive and they are the cause of most running toilets. Match the size, seat it flat, and check the chain has a little slack but not enough to slip under the flapper.
Then check the fill valve and float
If the water level is rising above the overflow tube, the fill valve is not shutting off and water is spilling down the tube continuously. That is a silent leak, which is why it can run for months undetected.
The level should sit about an inch below the top of the overflow tube. Adjust the float first. If the valve will not hold regardless of float position, replace it.
The problems that need a plumber
A tank that empties overnight with no colour in the bowl usually means a hairline crack. A toilet that runs and also rocks may have a failing flange, which is not a tank problem at all.
If you have rebuilt the tank and it still runs, the seat the flapper closes against may be pitted from mineral build-up. That is a fixable job but it needs the tank pulled.
What it costs to ignore
At even a slow leak rate, a running toilet adds up over a quarter. On a well and septic system it also means the pump is cycling and the drain field is taking water it does not need.
Water moving right now? Shut the main off first, then call (888) 809-6756. Dispatch is live open 24 hours, 7 days a week across every Florida city.