My toilet keeps running.
Let's figure out if this is a $15 problem or a plumber problem.
Time
15-30 min
Cost
$10-30
DIY?
Probably
Urgency
Low
What's probably happening
Almost always a worn flapper — the rubber seal at the bottom of the tank isn't sealing, so water keeps trickling into the bowl and the tank keeps refilling.
How urgent is it
Low urgency, but it's wasting water and money every hour it runs. Worth fixing this weekend, not this year.
What to do first
Lift the tank lid and watch the flapper after a flush. If it doesn't drop flat and seal, that's your culprit.
Can I handle this myself
Yes. Turn off the water valve behind the toilet, drain the tank, unhook the old flapper, and clip in a universal replacement from any hardware store.
When to call a professional
Call a plumber if the fill valve itself is broken, the tank is cracked, or you've replaced the flapper and it's still running.
What it might cost
A universal flapper is $10-15. If the whole fill valve needs replacing, budget $20-30 in parts, still a DIY job for most people.
What to gather first
None needed — just the model number on the tank if you want an exact-match part instead of a universal one.
Mistakes to avoid
Ignoring it because it's 'just water,' overtightening the flapper chain, and buying the wrong flapper size for older toilets.
Sources
General educational information, not individualized tax, legal, or financial advice for your situation.
Self-reported. Saved on this device only.
What you might need
A few things that actually help with this exact problem, not a random gear list.
Diagnose the problem first, and use tools or parts you already own when they'll do the job.
These links open retailer search results. Check compatibility and retailer details before buying.
Replacement toilet flapper
Check your toilet model and flapper size before buying. A replacement may help if the existing seal is worn.
Browse options on AmazonAdjustable Wrench
Useful for some repairs. A basic flapper replacement may not need one.
Browse options on AmazonToilet Tank Repair Kit
Only if your diagnosis calls for more than a flapper. Check the kit contents and toilet compatibility first.
Browse options on AmazonGot a confusing adulting question we haven't answered yet?
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