Quick answer
A toilet that keeps running is leaking from the tank into the bowl. If water spills into the overflow tube, the fill valve is not shutting off: lower the float or replace the valve. If the water is below the tube, test the flapper with a few drops of food coloring in the tank; color in the bowl after about ten minutes means the flapper leaks and needs replacing. Check the chain has a little slack. If new parts do not stop it, a plumber replaces the flush valve; toilet repairs run $150–$391 (HomeAdvisor). Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed October 27, 2026· Next review Apr 2027
A toilet that keeps running, refills on its own every few minutes or hisses all night is leaking from the tank into the bowl. It wastes water quietly: the EPA's WaterSense program notes that an old or worn flapper can let a toilet leak thousands of gallons a year without any visible puddle. The fix is usually one of two parts inside the tank.
Find Which Part Is Leaking
- 1Take the tank lid off and look at the water level. If water is running over the top of the overflow tube (the open pipe in the middle), the fill valve is not shutting off.
- 2If the water is below the tube, test the flapper. EPA's test: put a few drops of food coloring in the tank and wait about ten minutes without flushing. Color in the bowl means the flapper is leaking.
- 3Check the chain. A flush chain that is too short holds the flapper slightly open; one that is too long can tangle under it. Leave about half an inch of slack.
- 4Check the float. Lower the float (or turn the adjustment screw on the fill valve) so the water stops about an inch below the top of the overflow tube.
What Each Sign Points To
| What you see | Likely cause | Fix |
|---|---|---|
| Water spilling into the overflow tube | Fill valve not shutting off, float set too high | Adjust the float or replace the fill valve |
| Color shows in the bowl, water below the tube | Worn or warped flapper | Replace the flapper |
| Runs only after flushing until you jiggle the handle | Chain too short or tangled, sticky handle | Adjust the chain or handle |
| Hissing, tank never quite fills | Fill valve worn or debris in the valve | Clean or replace the fill valve |
| New flapper, still leaks | Pitted or cracked flush valve seat | Plumber: flush valve replacement |
| Water on the floor, not in the bowl | A different problem: see toilet leaking at the base | Plumber |
Flappers and fill valves are standard parts at any hardware store; take the old one with you to match it. If the tank is old, the bolts are corroded or the flush valve itself is cracked, the job involves taking the tank off, which is where most people call a plumber.
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One call reaches a plumbing company taking calls in your ZIP.
What a Repair Costs
HomeAdvisor's typical toilet repair runs $150–$391 (average $271), and Fixr puts simple jobs at $60–$200. A flapper or fill valve is a simple job; a flush valve that requires removing the tank costs more. The toilet repair page has the sources.
When to Call
Call if a new flapper and an adjusted fill valve have not stopped it, or if the tank has to come off. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
Why does my toilet keep running?
Either the fill valve is not shutting off and water spills into the overflow tube, or the flapper is leaking water from the tank into the bowl.
Why does my toilet refill by itself every few minutes?
Water is slowly leaking past the flapper, the tank level drops and the fill valve tops it up. A new flapper usually fixes it.
How much does it cost to fix a running toilet?
Fixr puts simple toilet repairs at $60–$200; HomeAdvisor's typical range for toilet repair is $150–$391. A flush valve that needs the tank removed costs more.
How much water does a running toilet waste?
EPA WaterSense notes that a worn flapper can let a toilet leak thousands of gallons a year.
Sources
- EPA WaterSense: Fix a Leak Week (flapper leaks and the food coloring test)
- HomeAdvisor cost guides (2025)
- Fixr cost guides (2025)
Methodology: How we source and verify data · Report an error
Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.
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