Toilet Keeps Running? Here's What's Actually Wrong (and What It's Costing You)
A toilet that runs is the most expensive cheap problem in a house. The parts cost a few dollars. The water it wastes, if you leave it three months, does not.
A continuously running toilet can push 150 to 200 gallons a day down the drain. On a Louisiana water and sewer bill, that is real money leaving quietly, without a puddle to warn you.
First, work out which kind of running you have
There are two patterns, and they point at different parts.
It runs constantly. Water never stops moving into the bowl. This is almost always the flapper — the rubber seal at the bottom of the tank — failing to seat, or the fill valve failing to shut off.
It runs in bursts, every few minutes. The tank is slowly losing water through the flapper, dropping the float, and triggering a refill. Plumbers call this phantom flushing. Same culprit, slower leak.
The dye test that settles it in ten minutes
Take the tank lid off. Drop a few drops of food coloring into the tank water. Do not flush. Wait ten minutes and look in the bowl.
Color in the bowl means the flapper is leaking. No color means the problem is on the fill side — the fill valve or the float height.
If the toilet is also rocking, or there is any dampness around the base, stop testing and call. That is a wax ring or flange problem, and it leaks into the subfloor rather than into the bowl.
The three usual causes
1. A worn or warped flapper
Rubber hardens with age and with chlorine. After five or six years it stops sealing flat. Replacement flappers are inexpensive and are the single most common fix. Match the size — most are 2 inch, some newer high-efficiency toilets are 3 inch.
2. A chain that is too short or too long
Too short and the flapper is held slightly open. Too long and it catches under the flapper as it drops. There should be a little slack, but not enough to tangle.
3. A fill valve that will not shut off
If water is running down the overflow tube in the middle of the tank, the fill valve is set too high or has failed. Adjusting the float lower fixes the first. A failed valve needs replacing, which is a twenty-minute job for a plumber and a frustrating afternoon for most homeowners.
When it is not the toilet at all
Occasionally what sounds like a running toilet is water moving somewhere else entirely — a supply line inside a wall, or a leak under the slab. The test is the same one that finds any hidden leak: shut every fixture in the house, then watch the water meter. If the dial still turns, something is leaking that is not a toilet.
That is a different job, and a more urgent one. Leak detection locates it without opening walls to look.
What we charge to fix it
Flapper and fill valve work is flat-priced and quoted before we start. If your toilet is old enough that parts are hard to source, or the tank is cracked, we will say so and price a replacement alongside the repair so you can compare the two honestly.
Call (833) 435-9778 and we will book a same-day slot.