Fix a Running Toilet
A toilet that won't stop running is usually a flapper or a fill valve. Most homeowners can fix it in under an hour if the shutoff valve works.
This is a judgment page, not a step-by-step how-to. The procedure lives in the vetted links at the bottom.
The call
If you can shut the water off and the bowl isn't rocking on a soft floor, replace the flapper or the fill valve yourself. Hire a plumber when the tank is cracked, the shutoff valve won't close, or water is showing up on the floor.
- Difficulty
- Time
- 30–60 minutes
- DIY estimate
- $8–$30
- Pro estimate
- $125–$250
1 of 5
Rough national estimate, not a quote. Prices move with the city, the brand, and whatever the job turns into once you open it up.
Tools
- TODO: affiliate link
Adjustable wrench or pliers
- TODO: affiliate link
Sponge and a small bucket
- TODO: affiliate link
Flashlight
Materials
- TODO: affiliate link
Toilet flapper that matches the old one
Take the old flapper to the store. The wrong one will still leak.
- TODO: affiliate link
Fill valve, if the float won't shut the water off
- TODO: affiliate link
Supply line, only if the old one is crusted or kinked
Affiliate slots are placeholders. A live shop link will be marked as sponsored. See the affiliate disclosure.
Safety notes
- Shut the water off at the toilet supply valve and confirm it stops before you loosen anything.
- If that valve spins, leaks, or won't close, shut the water off at the house main and hire a plumber to replace the valve.
- Don't overtighten plastic nuts or tank bolts. Porcelain cracks without much warning.
- Water on the floor, a rocking bowl, or a soft spot in the flooring is a leak into the structure. Stop and hire a plumber.
Do I need a permit?
A flapper or fill valve is ordinary repair in many places.
Swapping those parts usually does not need a building permit. Replacing the whole toilet can be a different question. Open your state page and read the toilet line. If it says to check locally, call the building department before you start.
On each state page, read: Toilet.
Permit triggers are local. This is general information, not legal advice. All state pages · Disclaimer
Best How-To Videos & Articles
We link to guides that already exist. We don't rewrite them.
- How to Fix a Running Toilet
Family Handyman · Article
- How To Fix a Running Toilet
This Old House · Article
- How to Fix A Running Toilet GUARANTEED | DIY Plumbing Repair
Roger Wakefield (YouTube) · Video
Questions people ask first
- Can I fix a running toilet myself?
- Yes, when the problem is a worn flapper or a fill valve and you can shut the water off. Hire a plumber if the tank is cracked, the toilet rocks, or the floor feels soft.
- How much does it cost to fix a running toilet?
- Parts are often $8–$30. A plumber visit for the same repair is often $125–$250. Those are rough national estimates, not a quote.
- Do I need a permit to fix a running toilet?
- Usually not for a flapper or fill valve. Check the toilet line on your state permit page, and call your local building department if that line tells you to.