Toilet Keeps Running? Here’s What’s Causing It and How It Can Quietly Cost You Hundreds

If your toilet keeps running, it’s more than an annoying sound, it’s one of the most common causes of hidden water waste in homes.
A running toilet can leak thousands of gallons of water per month, quietly inflating your water bill and stressing your plumbing system.
In South Florida, where water pressure, humidity, and older plumbing systems are common, running toilets happen more often , and get ignored far too long.
Let’s break down what’s actually happening inside the tank.
1. A Running Toilet Is Almost Always a Tank Component Failure
Inside the tank, several parts work together to stop water flow after each flush.
When one fails, water keeps flowing.
The most common culprits:
- worn flapper
- faulty fill valve
- stuck float
- misadjusted water level
- cracked overflow tube
None of these fix themselves.
2. The Flapper Is the #1 Cause
The flapper seals water inside the tank after a flush.
Over time, flappers:
- warp
- harden
- crack
- collect mineral buildup
When the seal fails, water leaks from the tank into the bowl nonstop , causing the toilet to refill endlessly.
Florida minerals speed this up.
3. Fill Valve Problems
The fill valve controls how much water refills the tank.
If it:
- sticks open
- wears internally
- gets mineral buildup
…the tank never stops refilling, even when full.
This often sounds like a constant hiss or refill noise.
4. Float Set Too High
If the float is set too high, water spills into the overflow tube.
That creates a silent, continuous refill cycle.
This is extremely common after DIY repairs.
5. Cracked or Misaligned Overflow Tube
If the overflow tube is:
- cracked
- too short
- loose
…water drains constantly into the bowl.
This is subtle but expensive.
6. How Much a Running Toilet Can Cost You
A toilet that runs continuously can waste:
- 200–300 gallons per day
- 6,000–9,000 gallons per month
That’s hundreds of dollars per year , from one toilet.
In some South Florida municipalities, water overuse also triggers higher-tier billing rates.
7. Signs Your Toilet Has Been Running for a While
- unexplained high water bill
- tank refilling randomly
- faint water movement sound
- bowl water level slowly changing
- mildew smell near toilet
- condensation forming around base
If you hear the tank refill without flushing , it’s running.
8. DIY Checks You Can Do
✔ lift the tank lid
✔ flush and watch the flapper
✔ check if chain is tangled
✔ look for water flowing into overflow tube
✔ gently press flapper down
If water stops only when you press the flapper → it’s failing.
9. Why DIY Fixes Often Don’t Last
Homeowners often replace one part , but ignore others.
Problem:
- new flapper + old fill valve
- float adjusted but valve worn
- mineral buildup left inside tank
This causes the problem to return within weeks.
10. When to Call a Plumber
Call a professional if:
- toilet keeps running after DIY fix
- water bill keeps rising
- multiple toilets run
- tank parts look corroded
- toilet is older than 10 years
- water pressure is high
- refilling noise is constant
These often require full tank rebuild or pressure adjustment.
11. What We Do (Professional Repair)
At Leading Plumbing Services, we:
- inspect all tank components
- replace worn flappers and valves
- adjust float levels correctly
- test water pressure
- clean mineral buildup
- rebuild tank if needed
- recommend toilet replacement if inefficient
We stop the running permanently, not temporarily.
12. Florida-Specific Reality
South Florida plumbing faces:
- mineral-heavy water
- higher water pressure
- faster rubber degradation
- older toilets in many homes
That’s why running toilets are one of our most common service calls.
Final Thoughts
If your toilet keeps running, you’re literally watching money go down the drain, even if you can’t see it.
Fixing it early:
- lowers water bills
- prevents tank damage
- reduces moisture and mold risk
- avoids emergency repairs
Call/Text us today to stop a running toilet for good:
(561) 506-6159





