Plumbing
Toilet Keeps Running? Causes and How to Fix It
A toilet that keeps running — that faint, endless trickle into the bowl — is quietly wasting water and adding to your bill every day. It’s usually a small worn part, and an easy fix once you know the cause. Here’s what’s going on.
Key takeaways
- A constant trickle usually means a worn flush valve/flapper or fill valve.
- It wastes water continuously — worth fixing promptly.
- The water level in the cistern being too high is another common cause.
- Cheap parts, but access and adjustment are fiddly — a plumber makes it quick.
Why toilets run
Most running toilets come down to the cistern’s internal parts. A worn flush valve seal (flapper) lets water leak continuously from the tank into the bowl. A faulty fill valve keeps topping the tank up, or an overflow caused by the water level being set too high sends water constantly down the overflow tube.
What the fix involves
The parts themselves are inexpensive — the job is identifying which component has worn, replacing it, and setting the water level correctly so the cistern fills and stops as it should. It’s a quick fix for a plumber and stops the ongoing waste immediately.
Don’t leave it
Beyond the wasted water, a constantly running toilet can wear other parts faster and, in some cases, points to sediment or wear that’s worth addressing while you’re at it.
Frequently asked questions
Why does my toilet keep running after flushing? Usually a worn flapper or fill valve, or the water level set too high.
Is a running toilet a big deal? It wastes water continuously and adds up on your bill, so it’s worth fixing promptly.
Are the parts expensive? No — the valves and seals are cheap; it’s a fast repair.
Can I fix it myself? Sometimes, but access and correct adjustment are fiddly — a plumber makes it quick and reliable.
Stop the waste
We fix running toilets and other cistern faults fast. See our plumbing service and read our toilet replacement cost guide. Get a free quote today.
