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Why is my toilet running constantly after flushing?

A constantly running toilet wastes water and annoys. Fix the flapper, fill valve, or float in minutes.

Category:Plumbing

Difficulty:Easy

Time:15 min

Success:50%

Updated:Jun 10, 2026

quick_referenceQuick Answer

For Why is my toilet running constantly after flushing?, start with "Check the flapper seal": Remove the tank lid. Flush the toilet and watch the flapper. If it doesn't drop fully or hangs up, clean or replace it. Stop DIY if you see water pooling on the floor around the toilet base. This is listed as a easy recovery and usually takes about 15 min.

verifiedGuide Snapshot

Repair areaPlumbing

Estimated time15 min

DifficultyEasy

Stop conditions3

Last updated Jun 10, 2026. Review the stop conditions before continuing.

account_treeRecovery State

DeviceToilet

Current stateLeak

Specific stateRunning Water

Failed stepFlapper Wear

Likely failure typeWorn Part

DIY boundaryDIY recovery first

paymentsCost decision

help1. Understand the Problem

A toilet that keeps running after flushing usually means the flapper isn't sealing, the fill valve is stuck, or the float is set too high. Water leaks from the tank into the bowl, causing the fill valve to keep running. This is a common, easy DIY fix.

build_circle2. Try This First

Best First Step

Check the flapper seal

Remove the tank lid. Flush the toilet and watch the flapper. If it doesn't drop fully or hangs up, clean or replace it.

visibility3. Visual Guidance

See what's happening and how to try the first recovery step.

Turn off water and flushTurn the shut-off valve clockwise. Flush to drain the tank.

Inspect the flapperCheck for cracks, warping, or mineral buildup. If worn, remove it by unhooking from the pegs.

Install a new flapperHook the new flapper onto the pegs, attach the chain with 1/4 inch slack, and test.

Adjust the floatIf water still runs, bend the float arm down or adjust the float screw so water stops at the fill line.

autorenew4. If That Doesn't Work

Try the next recovery options.

Replace the fill valveIf the flapper is fine, the fill valve may be worn. Replace the entire valve assembly.

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Frequently Asked Questions

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warning5. Stop DIY If

Don't continue if any of these apply.

reportYou see water pooling on the floor around the toilet base

reportThe fill valve is cracked and spraying water

reportYou are uncomfortable turning off the water supply

Still stuck?Get personalized help with AI Recovery.

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Toilet Fills SlowlyA slow-filling toilet tank can waste time and indicate a hidden problem. Learn how to diagnose and fix the fill valve or supply line.

Similar Failure Pattern

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This page provides general DIY guidance.
If you're unsure, it's always best to consult a professional.