Toilet Keeps Running

Why does your toilet keep running? Learn the causes, easy DIY fix, tools needed, and plumber cost ($75–$200). Fix it in 15 minutes.

Typical repair cost: $75–$200 · DIY difficulty: Easy · About 15–30 minutes.

What usually causes it

• Faulty flapper valve
• Float set too high
• Stuck fill valve
• Worn flush valve seal
• Chain too long or too short

What you need

• Replacement flapper
• Adjustable wrench (optional)

How to fix it yourself

1. Remove the tank lid and inspect the flapper
2. Flush and watch if the flapper seats properly
3. If worn, unhook old flapper and install a new one ($5–$10 at any hardware store)
4. Adjust the float so water stops about 1 inch below the overflow tube
5. If the fill valve is stuck, turn water off and replace it
6. Test by flushing several times

When to call a pro

If the toilet is cracked, rocking on the floor, or you've replaced parts and it still runs.

Get a fixed price from a local pro