Plumbing tips · October 9, 2026
Toilet keeps running?
A toilet that runs on and on, or refills by itself every so often, is quietly sending clean water down the drain. Most of the time the cause is one of three parts inside the tank.
Take the lid off and look
Lift the tank lid and watch the water. If it is pouring over the top of the tall open tube in the middle (the overflow tube), the fill valve is set too high or not shutting off. If the level looks right but you hear it trickling, water is leaking past the flapper at the bottom.
The flapper
The rubber flapper at the bottom of the tank is the most common cause. Over time it goes stiff or warped and stops sealing. To test it, put a few drops of food colouring in the tank and do not flush. If colour shows up in the bowl after a little while, the flapper is leaking.
The chain
A chain that is too short holds the flapper open a crack. One that is too long can get caught under it. It wants a little slack — just enough that the flapper sits flat when the handle is at rest.
The fill valve
The fill valve is the tall part on the left that refills the tank. The water should stop a little below the top of the overflow tube, and most tanks have a line marking where. If it will not shut off at that level, the fill valve needs adjusting or replacing.
Questions we get asked
How do I stop it running right now?
Turn the shut-off valve on the wall behind the toilet clockwise until it stops. The toilet will still flush once with what is in the tank.Does a running toilet really waste much water?
Yes. A steady leak runs all day and all night, and it is often enough to show up on the water bill before anybody notices the sound.When is it more than a running toilet?
Water on the floor around the base, a toilet that rocks, a crack in the tank, or a shut-off valve that will not turn or drips — those need a plumber rather than a new flapper.Plumbing questions we answer
Where we go
Parker, Wise and Tarrant County, out of the shop in Springtown. Springtown, Weatherford, Azle, Boyd, Decatur, Newark, Millsap, Fort Worth and the country in between.
Call 817-487-8866