What it usually means
| A worn flapper | The rubber seal at the bottom of the tank has gone soft or warped. Water seeps into the bowl and the tank tops itself up every few minutes. The most common cause by far. |
|---|---|
| The fill valve will not shut off | A constant hiss, and water running down the overflow tube. The valve is worn or the float is set too high. |
| The chain | Too short and it holds the flapper open. Too long and it gets trapped under it. |
| A cracked overflow tube or flush valve | Water disappears from the tank with a new flapper fitted. The flush valve itself needs replacing, which means taking the tank off. |
| High water pressure | Fill valves fail early and hiss when house pressure is too high. If you have replaced one twice, have the pressure checked. |
What to check yourself
- Put a few drops of food colouring in the tank and do not flush. If colour shows in the bowl within fifteen minutes, the flapper is leaking.
- Lift the lid and look at the water level. It should sit about an inch below the top of the overflow tube. If it is running into the tube, lower the float.
- Check the chain has a little slack and is not caught under the flapper.
- To replace a flapper: turn the valve behind the toilet clockwise, flush to empty the tank, unclip the old one and take it to the hardware store to match it.
- If you do not want to deal with it today, turn that valve off between uses. It stops the waste at once.
Call a plumber if
- A new flapper did not fix it
- Water is on the floor around the base
- The shut-off valve behind the toilet will not turn or drips when touched
- The tank is cracked
Call 1-800-604-0631, any hour.
What fixing it costs
A flapper or fill valve is a short job. Repairs like this are hourly: $289 for the first hour on site and $189 an hour after, in regular hours (9 to 5, Monday to Friday). Outside those hours every rate is double. See toilet repair for typical costs.
If the toilet is more than twenty-five years old, compare the repair with a new toilet. A modern one uses a fraction of the water.
Questions people ask
How much water does a running toilet waste?
A slow leak can waste a few hundred litres a day, and a fill valve stuck open far more. If you are on a water meter you will see it on the bill.
Why does my toilet run for a few seconds on its own?
That is called ghost flushing. The tank is slowly leaking into the bowl, and the fill valve tops it up when the level drops. It is the flapper.
Are in-tank cleaning tablets a problem?
Yes. Chlorine tablets sit against the rubber parts and wear out flappers and seals early. Many toilet makers say not to use them.