Toilet Keeps Running
A toilet that keeps running is almost always a worn flapper, a tangled chain, or a fill valve set too high so water spills into the overflow tube. Replacing a flapper costs under $15 and takes 10 minutes. A plumber typically charges $100 to $250 for the repair.
Typical pro cost
$100 to $250
- Urgency
- Fix soon
- DIY difficulty
- Easy
- Time to fix
- 10 to 30 minutes
- Prices
- US typical range
Last reviewed September 2026
Signs it's this problem
- Water keeps running into the bowl
- Tank refills on its own every few minutes (phantom flush)
- Hissing sound from the tank
- Water level above the overflow tube
Common causes
Worn flapper
The rubber seal at the bottom of the tank warps or hardens and lets water leak into the bowl.
Chain too short or tangled
Holds the flapper slightly open.
Float set too high
Water rises above the overflow tube and runs into the bowl constantly.
Failed fill valve
The valve does not shut off fully and keeps hissing.
Cracked overflow tube
Rare, but water drains continuously.
How to fix it, step by step
- 1
Lift the tank lid and watch a full flush and refill.
- 2
Add a few drops of food coloring to the tank. If color shows in the bowl within 15 minutes without flushing, the flapper leaks.
- 3
Check the chain: leave about 1/2 inch of slack.
- 4
If water runs into the overflow tube, lower the float by turning the adjustment screw or sliding the clip. The water line should sit about 1 inch below the tube.
- 5
Replace a leaking flapper: shut off the supply valve, flush to empty the tank, unhook the old flapper and clip on a matching new one.
- 6
If the fill valve still hisses, replace the fill valve; it is a 20-minute job with a universal kit.
Tools and materials
- Replacement flapper or fill valve kit
- Adjustable wrench
- Sponge and towel
- Food coloring
Approximate DIY cost: $5–$30
Call a pro when
- The shutoff valve behind the toilet leaks or will not turn
- Water leaks from the tank bolts or base
- Parts do not match an older or specialty toilet
Toilet Keeps Running cost
| Job | Typical cost |
|---|---|
| Plumber: replace flapper or fill valve | $100–$250 |
| Replace toilet shutoff valve | $100–$200 |
| Rebuild tank (all internal parts) | $150–$300 |
| New toilet, installed | $300–$800 |
Ranges are typical US prices compiled by FixHomeCost. Prices vary by region, home and contractor, so compare 2–3 local quotes.
Common questions
How much water does a running toilet waste?
A constantly running toilet can waste up to about 200 gallons a day, which can add noticeably to your water bill.
Why does my toilet run for a few seconds every few minutes?
That is a phantom flush. The flapper is leaking slowly, so the tank drops and refills. Replace the flapper.
Can I stop a running toilet temporarily?
Jiggle the handle to reseat the flapper, or turn off the supply valve behind the toilet until you can fix it.
How long does a toilet flapper last?
Usually about 4 to 5 years. Chlorine tablets in the tank shorten their life.
Related guides
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