Toilet Keeps Running? 3 Causes and 10 Minute Fixes

Q: What Parts Do You Need and What Do They Cost

PartPart costTime to swapFixes this symptomFlapper$5 to $105 minutesRefills on its own between flushesFill valve$10 to $2020 minutesConstant hiss, never shuts offFlush valve and gasket$15 to $3045 minutesLeak continues after a new flapperComplete tank rebuild kit$25 to $401 hourOld toilet with several worn partsA plumber visit for a running toilet usually lands in the $125 to $250 range once parts and labor are included, and that is the right call when the tank parts are not the problem.

Why Does Your Toilet Keep Running?

A running toilet is almost always caused by one of three things: a worn-out flapper (the rubber seal at the bottom of the tank), a faulty fill valve, or a float that's set too high. A running toilet can waste up to 200 gallons per day - that's $50-$100+ added to your monthly water bill. Here's how to diagnose and fix each cause.

1. Check the Flapper

The flapper is the rubber disc at the bottom of the tank that seals water in between flushes. Over time, it warps, cracks, or collects mineral buildup and stops sealing properly. Drop a few drops of food coloring in the tank - if color appears in the bowl within 15 minutes without flushing, the flapper is leaking. Replacement flappers cost $5-$10 and take 5 minutes to swap. This fixes about 60% of running toilets.

2. Check the Fill Valve

The fill valve controls water flowing into the tank after a flush. If it's worn out or stuck, it can run continuously. Listen: if the sound is a constant hiss, the fill valve is likely the problem. Replacement fill valves cost $10-$20 and most homeowners can swap them in 20 minutes with basic tools.

3. Adjust the Float

If the water level in the tank is too high, water continuously drains into the overflow tube. The float controls the water level - adjust it so the water stops about 1 inch below the top of the overflow tube. On a ball float, bend the arm down slightly. On a cup float, squeeze the clip and slide it down.

Who Is the Best Local Plumber for Toilet Repair in Central Illinois?

If the tank parts are not the problem, you need a licensed plumber who works in your town. Trouble Free covers plumbing in Pekin, IL, plumbing in Peoria, IL, and plumbing in East Peoria, IL. A constantly running toilet often shows up alongside slow drains, so if water is backing up too, look at professional drain cleaning or drain cleaning in East Peoria. See everything we handle on our plumbing services page.

When Should You Call a Plumber for a Running Toilet?

If you've replaced the flapper and fill valve and the toilet still runs, there may be a crack in the overflow tube, a warped flush valve seat, or an issue with the toilet itself. Older toilets (pre-1994) use 3.5-7 gallons per flush vs. 1.6 for modern low-flow models. If your toilet needs major repair, upgrading to a new one often makes more sense. Trouble Free handles toilet repair and replacement across Peoria, Pekin, Morton, Washington, and surrounding areas. To keep your home trouble-free, call (309) 347-5309.

How Much Water and Money Does a Running Toilet Waste?

A running toilet is metered water going straight down the drain. Here is roughly what different leak sizes add up to:

Leak size	Sound	Gallons per day	Added to a monthly water bill
Slow flapper seep	Silent, refills every few minutes	30 to 100	$5 to $20
Worn flapper	Refills every minute or two	100 to 200	$20 to $50
Stuck fill valve	Constant hiss	200 to 500	$50 to $100 or more
Overflow tube spill	Steady trickle inside the tank	up to 1,000	$100 and up

Dollar figures are estimates and depend on your local water and sewer rates. The point stands: the repair parts cost under $25 and pay for themselves in the first month.

What Parts Do You Need and What Do They Cost?

Part	Part cost	Time to swap	Fixes this symptom
Flapper	$5 to $10	5 minutes	Refills on its own between flushes
Fill valve	$10 to $20	20 minutes	Constant hiss, never shuts off
Flush valve and gasket	$15 to $30	45 minutes	Leak continues after a new flapper
Complete tank rebuild kit	$25 to $40	1 hour	Old toilet with several worn parts

A plumber visit for a running toilet usually lands in the $125 to $250 range once parts and labor are included, and that is the right call when the tank parts are not the problem.

How Do You Stop a Toilet From Running Right Now?

If it is running and you cannot fix it this minute, shut the supply off. The shutoff is the small oval or round valve on the wall behind the toilet, near the floor. Turn it clockwise until it stops. The tank drains and the running stops, and you can still flush by pouring a bucket of water into the bowl. This buys you time without paying for wasted water.

Can a Running Toilet Cause Damage or Higher Sewer Charges?

Yes on both. Many Central Illinois utilities bill sewer based on metered water use, so a leaking toilet raises two lines on the bill instead of one. A constantly wet flapper also wears the flush valve seat, and a tank that never stops filling can push water past the overflow tube and onto the floor if the fill valve fails hard. It is a small repair that gets expensive when ignored for months.

When Is It Time to Replace the Toilet Instead?

Replace rather than repair when the bowl or tank is cracked, when the toilet rocks and the flange is damaged, when you have rebuilt the tank once already, or when the fixture predates 1994 and uses 3.5 gallons or more per flush. A modern 1.28 gallon toilet cuts water use by more than half on every flush.

Get a Running Toilet Fixed by a Licensed Plumber

If a new flapper and fill valve did not stop it, the problem is in the flush valve, the seat, or the fixture itself. Our licensed plumbers handle toilet repair and replacement across Pekin, Peoria, Morton, Washington, East Peoria, and Canton, with a flat price quoted before the work starts.

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Why Does My Toilet Keep Running?