Will Your Toilet Not Stop Running? Here's How to Fix It.
That constant sound of trickling water. The handle jiggles, which only works for a minute. The nagging worry about your water bill climbing higher each month.
As Atlanta's trusted plumbing experts, we've seen thousands of homeowners struggle with toilets that won't stop running. The good news? About 80% of running toilets can be fixed in less than 30 minutes with a $15 part and basic tools you already own.
But before you start dismantling your toilet tank, let's walk through the seven most common causes, how to diagnose your specific issue, and when it's time to call in professional help.
How Your Toilet Actually Works
Understanding the basic mechanics of your toilet makes troubleshooting much easier. Here's what happens when everything works correctly:
When you push the handle, a chain lifts a rubber flapper at the bottom of your tank. Water rushes from the tank into the bowl, flushing away waste. As the water level drops, the flapper falls back down and seals the opening. Meanwhile, a float (either a ball or cup) drops with the water level, triggering the fill valve to turn on and refill the tank.
As the tank fills, the float rises. When it reaches the proper height, it shuts off the fill valve, and water stops flowing. Simple, right?
When this system works correctly, your toilet fills quietly and stops. But when any component fails, you end up with a toilet that won't stop running.
The 7 Most Common Causes (And How to Fix Each One)
Reason #1: Worn-Out Flapper
This is your culprit about 80% of the time. The flapper is the rubber seal at the bottom of your tank. Over time, mineral deposits, chlorine, and age cause it to become stiff, warped, or cracked. When it doesn't seal completely, water slowly leaks into the bowl, triggering the fill valve to keep running.
The Diagnosis Test: Drop a few drops of food coloring into your toilet tank. Wait 15 minutes without flushing. If colored water appears in the bowl, you have a leaky flapper.
The Fix: Shut off the water valve under your toilet. Flush to empty the tank. Unhook the old flapper from its hinges and disconnect the chain. Take it to any hardware store for an exact match. Install the new flapper, making sure to clean any mineral buildup from the flush valve seat first.
Cost: $5 to $15 and about 10 minutes of your time.
Reason #2: Chain Issues
Even a brand-new flapper won't work if the chain isn't adjusted correctly. Too short? It holds the flapper open, allowing constant water flow. Too long? It gets tangled under the flapper, preventing a proper seal.
The Diagnosis Test: Lift your tank lid while the toilet is running. Watch the chain. Is it pulling the flapper up slightly? Is it tangled?
The Fix: Adjust the chain to have about half an inch of slack when the flapper is closed. You can move it to a different hole in the flush lever or clip it shorter. Make sure any excess chain won't get caught under the flapper.
Cost: Free. Takes less than five minutes.
Reason #3: Float Set Too High
Your float tells the fill valve when to shut off. If it's set too high, water fills above the proper level and spills into the overflow tube (that tall pipe in the center of your tank). The fill valve never shuts off because the water level never reaches the correct height.
The Diagnosis Test: Look in the tank while it's running. Is water flowing over the top of the overflow tube?
The Fix: For a ball float (a round ball on an arm), gently bend the arm downward. For a cup float (slides on the fill valve), pinch the adjustment clip and slide it down about an inch. The water should stop about one inch below the overflow tube's top.
Pro Tip: While you're checking the float, shake a ball float to see if water sloshes inside. If it does, the float has a leak and needs replacement.
Reason #4: Failed Fill Valve
The fill valve controls water flow into your tank. When it fails due to age, mineral buildup, or debris, it may not shut off even when the float reaches the correct height. You'll hear a constant hissing sound.
The Diagnosis Test: Lift the float all the way up with your hand. If water keeps flowing, the fill valve is faulty.
The Fix: Turn off the water supply. Flush to empty the tank. Disconnect the water line from the tank bottom. Unscrew the locking nut holding the fill valve and remove it. Install a new fill valve following the manufacturer's instructions.
Cost: $15 to $25 for the part, 30 to 45 minutes of work.
Not comfortable with this repair? Call a professional plumber who can handle it quickly.
Reason #5: Disconnected Refill Tube
The refill tube is a small, flexible tube running from the fill valve to the overflow tube. Its job is to refill the bowl after each flush. If it becomes disconnected or positioned wrong, water sprays around the tank instead of going where it should, tricking the float into thinking the tank isn't full.
The Diagnosis Test: Watch the tank refill after a flush. The refill tube should direct water into the overflow tube, not spray it elsewhere.
The Fix: Clip the refill tube back onto the overflow tube about an inch below its top.
Cost: Free. Takes 30 seconds.
Reason #6: Damaged Flush Valve Seat
Even a new flapper won't seal if the surface it sits on (the flush valve seat) is damaged. Years of mineral deposits can create an uneven, pitted surface that prevents any flapper from sealing properly.
The Diagnosis Test: You've replaced the flapper and adjusted the chain, but the toilet still runs. Run your finger around the flush valve seat. Does it feel rough or uneven?
The Fix: For minor buildup, use fine-grit emery cloth or a pumice stone to gently smooth the surface. For severe damage, you'll need to replace the entire flush valve assembly, which requires removing the tank from the bowl. At that point, professional toilet repair makes more sense.
Reason #7: Stuck Flapper
Sometimes the flapper physically gets stuck in the open position. The chain catches it, debris wedges it open, or the hinge binds up. Water pours continuously from the tank to the bowl.
The Diagnosis Test: The tank won't fill, and water flows constantly. Lift the lid and look. Is the flapper stuck up?
The Fix: Push the flapper closed. If it sticks again, identify why. Chain too short? Adjust it. Debris in the way? Clean it out. Flapper warped? Replace it with the correct type for your toilet model.
What a Running Toilet Really Costs You
Here's why you shouldn't ignore that running toilet:
Water Waste: A constantly running toilet wastes 200 gallons per day. That's 6,000 gallons per month, more water than two people typically use in a day.
Financial Impact: Even a slow leak wastes 20 to 30 gallons daily. Depending on your local water rates, a running toilet adds $50 to $200 to your monthly bill.
Environmental Cost: Fresh water is precious. Letting a toilet run wastes thousands of gallons that could be put to better use.
The good news? Fixing a running toilet is one of the easiest ways to cut water consumption and lower your utility bills immediately.
Quick Emergency Fixes
Need to stop your toilet from running right now while you wait for parts or professional help?
Jiggle the handle: Sometimes the chain catches. A quick jiggle releases it and lets the flapper drop.
Push the flapper down manually: Lift the lid and press the flapper to ensure it's seated properly.
Lower the float temporarily: If water's pouring over the overflow tube, bend the float arm down or slide the float cup lower.
Turn off the water: As a last resort, turn the shutoff valve under the toilet clockwise. You won't be able to flush, but you'll stop wasting water.
When DIY Isn't Enough
Most running toilet problems are straightforward DIY fixes. But some situations require professional attention. Consider calling an experienced toilet repair specialist if:
- You've replaced the flapper and adjusted everything, but the toilet still runs
- You're not comfortable replacing the fill valve
- The flush valve seat is severely damaged
- You notice cracks in the toilet tank
- Water leaks from around the toilet base
- Multiple fixes haven't solved the problem
A licensed plumber has specialized tools and experience to diagnose problems quickly. Sometimes paying for expert toilet repair services saves you time, frustration, and money spent on unnecessary parts.
Preventing Future Problems
Once your toilet stops running, keep it that way:
Replace flappers every 3 to 5 years: Don't wait for failure. Flappers are cheap and easy to replace. Make it part of regular maintenance.
Skip drop-in tank cleaners: Those blue tablets corrode rubber flappers and gaskets, causing premature failure. Clean your bowl manually instead.
Check your toilet twice yearly: Do the food coloring test. Adjust the float if needed. Inspect the flapper for wear. If you're not comfortable with these checks, schedule regular toilet maintenance services.
Address hard water: Mineral buildup accelerates component wear. Consider a water softener to protect all your plumbing fixtures.
Fix small issues immediately: That occasional running sound? Don't ignore it. What starts small often becomes a toilet that runs constantly.
Your Questions Answered
Why does my toilet keep running after flushing? The most common causes are a worn flapper, incorrect chain adjustment, or a float set too high. These account for about 90% of running toilet issues.
How do I get my toilet to stop running immediately? Try jiggling the handle or manually pushing the flapper down. For a permanent fix, work through the seven causes above to identify your specific problem.
My toilet still runs with a new flapper. Why? Check the chain length, inspect the flush valve seat for damage, and verify you have the correct flapper type for your toilet model.
Can a running toilet fix itself? No. The problem only gets worse over time, wasting more water and costing more money. You need to identify and fix the cause.
How long does it take to fix a running toilet? Most repairs take 10 to 30 minutes once you've identified the problem. Simple adjustments take minutes, while replacing parts might take 30 to 45 minutes.
Your Local Toilet Repair Experts
Whether you're in Marietta, Kennesaw, Alpharetta, Roswell, Sandy Springs, Smyrna, or anywhere in the Atlanta metro area, Dalmatian Plumbing is here to help with all your plumbing needs. Our experienced technicians provide reliable toilet repairs, replacements, and maintenance services that keep your home running smoothly.
Don't let a running toilet waste another dollar from your water bill. Contact us for 24/7 emergency service or schedule an appointment at your convenience.
