That hissing or trickling sound from your bathroom is easy to tune out. But if your toilet keeps running after every flush, or seems to run randomly even when no one is using it, it is costing you real money every single day.
A running toilet can waste up to 200 gallons of water per day. That adds up to more than 6,000 gallons a month and over 70,000 gallons a year. In Acadiana, where water rates are modest compared to other parts of the country, that still translates to an extra $20 to $70 or more on your monthly water bill depending on the severity of the leak. Ignore it long enough and you could be looking at several hundred dollars a year thrown away on water you never used.
The good news is that a running toilet is usually one of the more straightforward plumbing problems to diagnose and fix. Here is a clear look at what causes it, what it is actually costing you, and when it is time to pick up the phone.
How a Toilet Is Supposed to Work
Understanding why a toilet runs constantly starts with knowing how it is supposed to work in the first place.
When you flush, water rushes from the tank into the bowl through the flush valve opening, which is controlled by the flapper. Once the tank empties, a float drops and triggers the fill valve to bring fresh water back in. As the tank refills, the float rises. When the water reaches the correct level, the fill valve shuts off. The flapper reseats itself at the bottom of the tank, sealing everything until the next flush.
When any part of this process breaks down, water keeps moving when it should not. That is what you are hearing.
The Most Common Causes of a Running Toilet
A Worn or Damaged Flapper
The flapper is the rubber seal at the bottom of your toilet tank. It lifts when you flush and drops back into place to stop water from flowing into the bowl between flushes. Over time, the rubber degrades, warps, or develops mineral buildup, especially in areas with harder water. When the flapper does not seal properly, water slowly leaks from the tank into the bowl, and the fill valve keeps running to compensate.
This is the most common cause of a constantly running toilet and one of the easiest to fix. A replacement flapper costs just a few dollars at any hardware store and takes about 10 minutes to swap out.
A Float That Is Set Too High
The float tells the fill valve when to stop adding water. If the float is adjusted too high, the water level rises above the overflow tube and drains continuously, which means the fill valve never shuts off.
You can usually spot this by looking inside the tank. If water is spilling into the overflow tube, the float needs to be adjusted down. On older toilets with a ball float, you can bend the arm slightly downward. On newer fill valves with a cylinder float, there is typically an adjustment screw or clip.
A Faulty Fill Valve
If the fill valve is worn out or damaged, it may not shut off completely even when the float is in the correct position. You will often hear a constant hissing sound if this is the issue. Fill valves can be replaced without pulling the entire toilet, but it does require turning off the water supply and draining the tank.
A Chain That Is Too Long or Too Short
The chain connects the flush handle to the flapper. If it is too short, it holds the flapper up slightly, allowing water to leak through constantly. If it is too long, it can get caught under the flapper and prevent a proper seal. Either way, the fix is simple. You just need to adjust the chain length so there is a small amount of slack without excess.
An Overflow Tube That Is the Wrong Height
The overflow tube is the vertical tube inside your tank that acts as a backup in case the fill valve fails. Water drains into it before it can overflow the tank entirely. If the tube is too short or set at the wrong height, water may constantly run into it even at the correct fill level. Fixing this usually means replacing the entire flush valve assembly.
How Much Is a Running Toilet Costing You?
Here is a simple way to think about it. A moderate toilet leak can waste around 6,000 gallons of water per month. At typical Acadiana water rates, that comes to roughly $30 to $70 in extra charges on your bill each month, sometimes more depending on your utility provider and whether sewer charges are calculated based on water usage.
Over a year, that is $360 to $840 or more going straight down the drain. And more severe leaks can push that number significantly higher.
The repair cost, by contrast, is almost always far less. A DIY fix using a flapper or fill valve kit from a hardware store usually runs $10 to $30 in parts. A professional plumber can typically diagnose and repair a running toilet in under an hour for $150 to $300 in most cases. Either way, you recover that cost quickly through the water savings.
How to Check If Your Toilet Is Actually Leaking
Sometimes a toilet runs silently. You might not hear anything, but water is still trickling from the tank into the bowl. An easy way to check is the food coloring test.
Remove the tank lid and add a few drops of food coloring into the tank water. Wait 15 minutes without flushing. Then look at the water in the bowl. If the color has appeared in the bowl, your flapper is not sealing properly and water is leaking through.
Can You Fix a Running Toilet Yourself?
In many cases, yes. If the problem is a worn flapper or a simple float adjustment, it is a manageable project for a homeowner with basic comfort around plumbing. Turn off the water supply valve behind the toilet, flush to drain the tank, and follow the instructions that come with any replacement parts.
That said, there are situations where calling a professional is the smarter move:
- You have tried the simple fixes and the toilet is still running
- The problem is not obvious after checking the flapper, float, and chain
- You hear hissing but the water level looks correct
- The toilet is old and multiple components appear worn
- There is water at the base of the toilet or signs of a leak outside the tank
If the issue turns out to be the fill valve, flush valve, or something more involved, a professional plumber can handle it quickly and make sure the repair holds. Southern Air’s plumbing repair team serves the Acadiana area and can diagnose and fix toilet problems the same day in most cases.
When to Think About Replacing the Toilet Instead
Most running toilet issues are worth repairing. But if your toilet is 20 or more years old and has been repaired multiple times, replacement may be the more cost-effective path. Older toilets often use 3.5 to 6 gallons per flush. Modern high-efficiency toilets use 1.28 gallons or less. The water savings from switching to a newer model can be significant over time.
If you are already working with our bathroom plumbing team on another repair, it is worth asking whether your current toilet makes sense to keep.
Other Plumbing Issues That Can Drive Up Your Water Bill
A running toilet is one of the most common causes of an unexpectedly high water bill, but it is not the only one. If you fix the toilet and your bill stays high, it may be worth looking at:
- Dripping faucets or fixtures
- A slow leak somewhere in your supply lines
- An issue with your water softener cycling incorrectly
- A sewer or drain problem affecting your usage
Our leak detection service can help identify hidden water waste throughout your home.
Ready to Get Your Toilet Fixed in Acadiana?
Southern Air has been serving the Acadiana area since 1984. Our licensed plumbers offer upfront, honest pricing and same-day service in most cases. Whether it is a quick flapper replacement or a more involved repair, we will diagnose the problem clearly and give you a price before any work begins.
Call us at (337) 202-5755 or schedule online to book a plumbing appointment today.
