Key Takeaways
Running toilets are common and can waste hundreds of gallons each day. Use this guide to spot the signs, understand the most likely causes and know when to bring in a plumber.
A toilet that constantly runs can cause all kinds of issues for your household. The sound is annoying, but it can also cost you money. A running toilet can waste up to 200 gallons of water per day, which can add up fast.
Unfortunately, running toilets are very common. Any issue that allows water to leak from the toilet’s internal system can cause that nonstop flow.
Below, we go into the most common causes and how homeowners can identify them, along with when it’s time to call in a plumber.
Quick Checklist
Use this short to-do list to help you figure out what might be going on.
- Listen for hissing, trickling or constant refilling.
- Lift the tank lid. Does the flapper sit flat?
- Check the chain. Is it too tight? Too loose or tangled?
- Look at the water level. Is it flowing into the overflow tube?
- Check the handle. Does it stick or feel loose?
What Should a Homeowner Do If They Notice Any of These Signs?
If something looks off, try a quick adjustment like repositioning the flapper, float or chain. If the toilet keeps running, or you’re unsure what’s causing it, it’s best to call in a licensed plumber before the issue gets worse.
Common Reasons Your Toilet Is Running
If the quick fixes didn’t help, these problems are often to blame:
- An issue with the lift wire or chain
- A damaged or defective flapper
- Handle and flush rod issues
- Damaged wax seal
- Float issues
- Refill or overflow tube problems
- Cracked toilet bowl or trap blockage
- Water supply problems
Let’s dive into each of these.
1. An Issue With the Lift Wire or Chain
Inside your tank, a chain or wire connects the handle to the flush valve. If it becomes tangled, rusted or broken, the toilet may not flush completely, and the water keeps running.
Signs:
- Loose or overly tight chain
- Toilet won’t flush all the way
- Chain gets caught under the flapper
DIY difficulty: Easy. Untangling or replacing the chain usually fixes this issue.
When to call in a plumber: If the chain is fine but the toilet still won’t flush properly, the problem may be deeper in the flush mechanism.
2. A Damaged or Defective Flapper
The flapper seals the opening between the tank and the bowl. When it warps, cracks or misaligns, water can leak through, causing the toilet to run.
Signs:
- Toilet refills every few minutes
- Toilet won’t flush completely
- You see water trickling from the tank to the bowl
DIY difficulty: Easy. Replacing a flapper takes around 10 to 20 minutes.
Plumber needed if: You replace the flapper and the leak continues. This may mean the flush valve itself is damaged.
3. Handle and Flush Rod Issues
The handle should move the flush rod smoothly. If these parts loosen, the toilet may partially flush and keep running.
Signs:
- Handle feels loose or sticks
- Toilet flushes weakly
- Running sound continues after flushing
DIY difficulty: Moderate. Tightening the mounting nut can help, but overtightening can break the handle.
Call in a plumber if: The handle assembly is corroded or won’t stay tightened.
4. Damaged Wax Seal
The wax ring at the base of the toilet creates a watertight seal between the toilet and the floor drain. If it fails, water can leak under the toilet.
Signs:
- Water around the base
- Musty odors
- Toilet shifts slightly
DIY difficulty: Hard. The toilet must be removed entirely.
Plumber needed: Always. This is a task that a plumber needs to do.
5. Float Issues
The float controls the water level in the tank. If it’s set too high or becomes water-logged, water spills into the overflow tube, and the toilet won’t stop running.
Signs:
- Water draining into overflow tube
- Tank overfilling
- Toilet runs on and off
DIY difficulty: Moderate. Adjusting the float is simple, but replacing it is difficult.
Plumber needed if: Adjustments don’t help, or the fill valve also needs replacement.
6. Refill or Overflow Tube Problems
If the refill tube is too long or positioned incorrectly, it will constantly feed water into the bowl.
DIY difficulty: Moderate.
Call in a plumber if: You’re unsure how to reposition it without damaging other parts.
7. A Cracked Toilet Bowl or Trap Blockage
Cracks or internal blockages can affect how the toilet flushes and refills.
Signs:
- Lingering smells
- Visible cracks
- Repeated partial flushes
Plumber needed: Always.
8. Water Supply Problems
Leaks can develop at the shutoff valve, supply tube or water supply valve. These can cause running-water sounds and visible leaks around the toilet.
Plumber needed: Always. These leaks can worsen quickly, so you don’t want to take a chance with a DIY fix.
Why Is My Toilet Running Intermittently?
If your toilet randomly starts and stops running, the issue is usually one of these:
- Worn-out flapper: Water slowly leaks between tank and bowl, causing occasional refills.
- Chain too short or long: Keeps the flapper from sealing, or prevents it from lifting.
- Float or refill tube mispositioned: Water level fluctuates.
Most of these fixes are simple, but if adjustments don’t help, there may be a deeper issue, like a cracked valve or faulty fill assembly. A plumber can efficiently diagnose the root cause and fix the issue.
How To Replace a Toilet Flapper
If you are more comfortable with DIY tasks and want to try replacing your toilet flapper, follow these steps:
- Make sure to buy the correct flapper for your toilet model.
- Turn off the water supply and flush the tank empty.
- Remove the old flapper and attach the new one to the chain and valve.
- Turn the water back on, flush and check the seal.
If the toilet keeps running afterward, there are likely multiple issues happening at once. At this point, it’s time to call in a professional.
If DIY Fixes Don’t Work
Some issues aren’t visible from the tank, including:
- Cracked overflow tubes
- Leaks under the toilet base
- Problems with the fill valve assembly
- Hairline cracks inside the tank or bowl
If you’ve checked the basics and the toilet still runs, a licensed plumber can diagnose the hidden causes and address them.
What Our Customers Say
“It’s such a comfort to know that when something goes wrong (like today’s toilet leak) I will find kind and professional people ready to come out when I call ABC.”
— Dell H.
What to Expect From a Plumber
A professional will:
- Inspect all internal tank components
- Test the fill valve and flush valve
- Check the water supply and shutoff valve
- Look for cracks or hidden seal failures
- Make adjustments or replace faulty parts
Repairs are usually quick, and most homeowners get their toilet running properly the same day.
Frequently Asked Questions About Running Toilets
Why does my toilet only run at night?
Does a running toilet waste a lot of water?
Can a running toilet cause damage outside the bathroom?
ABC Can Get Your Toilet Working Again
Dealing with a running toilet can be frustrating and time-consuming. Instead of attempting a DIY fix, contact ABC Home & Commercial Services. Our licensed plumbing pros can diagnose the issue and get your toilet working again. We even offer 24/7 emergency service.
