Leaking Toilet Flapper? Learn Why It Leaks & How To Fix It (2022)

You may assume that the toilet flapper lasts the lifetime of your toilet. Wrong!

Truth is, toilet flappers are not something that you set and forget. When you skip the maintenance, you may get into trouble – the displeasure of a sticky, gunky, hardened, and degraded flapper seal. Eventually, you can get in a situation of a toilet flapper leaking water.

Unfortunately, minor or slow leaks caused by a toilet flapper can go unnoticed with relative ease. Yet, water continuously running into your toilet tank may affect your water bills. Expect up to 5 gallons of wasted water per day and a bill of hundreds. More than an annoying water trickle, a faulty toilet flapper can cause overflows, pink toilet mold, or even worse, flooding to your home.

Still, if you are lucky and proactive enough, a toilet flapper leak could be easy to detect and fix. Here, the Twin Home Experts – the go-to plumbers in Los Angeles – will gladly “leak” some pro advice, so you can problem-solve and avoid this nasty running toilet in the future.

Let’s dive in!

But First: How Does The Toilet Flapper Work?

To fix toilet flapper problems, you need to know how this part works. A toilet flapper valve, simply put – acts as a plug, regulating the water flow to and out of the toilet tank after flushing. How?

The toilet part opens up once there is a demand for draining water from the tank. The flapper closes when enough water is drained down into the bowl, and the tank fills slowly back up with water. But when the watertight seal deteriorates, it’s most likely to end up with a ghost flushing.

(Video) Fixing A Leaky Flapper Valve ~ Rick's Tips

Symptoms Of A Leaking Toilet Flapper

Even the sturdiest toilet flapper can become problematic. The tell-tale signs that you might have a malfunctioning flapper are:

  • Toilet water runs intermittently or for a longer amount of time than usual;
  • Rippling water move in the bowl between flushes;
  • Low flushing power and hissing “filling” sounds;
  • Jiggling the toilet handle doesn’t stop the toilet from flushing;
  • Wet toilet tank, mold, mildew growth, and funny smells;
  • Water bills higher than expected;
  • Flood can be a potential scenario if you left your dwelling unattended for a long time.

No prize for guessing whether the issue is water damage-threatening. It’s always best to entrust the issue to a professional plumber who has the experience and know-how to repair the leaking toilet issue right away.

Need professional help now? Call 877-941-1640 or message us online for a free inspection. We offer a same-day plumbing service!

Why Is Your Toilet Flapper Leaking?

#1 – Outdated Flapper

As time goes by, toilet flappers become less efficient because of dirt and sludge build-up around the seal. That’s normal – these parts are “perishable” and typically leak, often because of their intensive use.

Perhaps surprisingly, your hard-working toilet flapper simply needs a little maintenance and, apart from being covered with blemishes, can last between 3 and 5 years (sometimes more, if you are lucky). There are certain cleaning products formulated to help remove deposits from submerged elements. The mixture of baking soda, hot water, and white vinegar is a cheap and effective solution, also working inside your tank.

#2 – Drop-in Toilet Cleaners

“To drop chemical tablet cleaners into the tank can cause even the chemical-resistant rubber, silicone, or plastic flappers to deteriorate sooner than you expect, and lead to a never-ending flush.”, commented Harry H. Knowles, a certified toilet plumbing professional. Home maintenance and improvement franchise company operating across the UK and Australia. “A fresh-scent toilet might be a flush away, but in-tank cleaners should be your last resort. Yet, if you tend to use bleach-chlorine tablets, expect a brittle flapper in a year or so. Another potential hazard is that these tiny bits of toilet tank cleaners can get stuck into the flush valve, preventing the cistern from refilling after flushing. Worse, you can invalidate your toilet warranty if damage like a leaky flapper happens”, the expert adds.

#3 – Hard Water

For you, hard water may not pose any health risks. But over time, water mineral deposits and higher pH levels leave behind residue that sticks to the inside of your toilet flapper elements. If your home or office is located in the US “hard-water” areas, consider your toilet flappers more vulnerable to crumble, warp, and cracks.

(Video) How to Test for and Fix a Leaky Toilet Flapper

Also worth noting: You can preempt preventable damages if you have a water softener installed. All you need is a little plumbing work, a drain, and a power source if the model requires it.

#4 – High Water Pressure

This is a much more unlikely situation, however, it can happen. In order for your toilet flapper to drain an adequate quantity of water down the bowl, the water pressure needs to be adequate. If the pressure is too high, your plumbing appliance will tell you by the readings of your water pressure gauge. Or, it will simply break down.

Keep in mind that domestic water pressure sweet spots are usually between 30 and 60 PSI. And neither your internal toilet parts nor your kitchen appliances can withstand a pressure force of over 80 PSI.

Thumbs up to those of you who already have pressure reduction valves installed to protect the health of the plumbing system and appliances.

#5 – Bacteria Life In Water

The existence of bacteria, algae, and rotifer habitats in the toilet tank water is a common reason for a malfunctioning flapper valve. All of them prematurely deteriorate the tank fittings. The solution for a long-lasting flapper is to pick one that actively inhibits bacteria growth and is hard-water resistant. Keep in mind that the best flapper models are made of anti-corrosion and anti-fungal compounds to prevent early malfunctions.

#6 – Chain Too Loose

The guilty component could be the chain link that holds the flapper and the handle arm. If it’s too long, it can get caught under the flapper after you flush, resulting in intermittent but substantial tank leaking. Don’t worry, you can make a simple adjustment by hand to bridge the problem over. Then, flush the toilet to check if it works.

#7 – Chain Too Tight

Often, a short or stuck flapper chain can make it impossible for the flushing mechanism to work properly. The most obvious symptom is the feeling of tension when you push the handle. The fix? You can adjust the flapper-chain combo slack at about ½ inch, so it can do its essential job.

How To Check For A Toilet Flapper Leak?

You’ve let your faulty decade-old flapper pile up hundreds of $$$ water bills, and now, you realize it’s time to check if the symptom of trickling water between flushes is a real danger. Here’s what to do before you set about changing your flapper:

  • Perform a food coloring test. Your first port of call is to make a dye test, which will reassure you if you need to replace the flapper. All you have to do is to lift the lid after you have the flush button off. Then, pour 10-20 drops of green/blue food coloring in the tank and let the substance sit for an hour. Blame the flapper for the toilet leak if the dye has made its way into the bowl. The faster it seeps into the bowl, the more serious the water leak is. Our verdict? Fix or replace your toilet flapper assembly.
  • Check if the flapper snugly seals against the flush valve. If you find yourself questioning whether the flapper seals properly, inspect its rubber element for nicks or irregularities with the help of a finger. The situation might be that your flapper lost its flex to provide a secure seal, causing a continual supply of water to the toilet bowl. Apply a couple of thrusting (but gentle) motions to get it to fit properly in the flush valve. Though, you still need to replace it before the problem escalates.

How To Replace Your Leaking Toilet Flapper With a Trouble-Free One?

Is your toilet flapper not closing? Is it outdated and inefficient? Is your toilet mechanism out of warranty?

(Video) Common Toilet Flapper Problems and Solutions/Leaky Toilet Fixes.

Your intuition is right. You can cut the safety-related risks – including mold growth, toilet overflows, and water damage – by installing a new, leak-free toilet part. Luckily, the change of a toilet tank flapper needs only a new unit ($10-$30) and is a 15 min, easy-to-do DIY project. No need for special tools or toilet removal.

Apart from luck, gear up with the Twin Home Experts tips for changing a worn-out toilet flapper and achieve your goal faster and with fewer problems:

Step #1 – Shut The Water Off And Empty The Tank

Before you get busy with the flapper disassembly, your first job is to locate the main water supply valve. Turn its handle clockwise – with a disconnected water supply, the tank will no longer refill. For an extra measure of safety, flush the toilet several times to help the tank drain completely.

Step #2 – Dismount The Faulty Component

To disassemble, it is a matter of raising the toilet lid and locating the black or red rubber/plastic flapper down at the bottom of the tank. Next, disconnect the flapper from the left and right tab of the overflow tube and unhook the chain from the toilet handle arm. With the defective flapper off, next, pull it out.

A useful tip is to take a couple of pictures from different angles of your tank mechanism, so you know how to restore the configuration at a later stage of the process.

Step #3 – Clean The Seal Beneath Your Flapper Location

As mentioned earlier, at this step, you might realize that the flapper is not faulty but covered with grime or dirt. Before you run to the nearest DIY store, give the flapper and everything around its seat a good clean-up with a mild, natural cleaning solution. Then, make sure the seal is smooth to the touch. Otherwise, the connection with the flapper won’t be watertight. Finally, it’s worth testing the toilet for leaks one more time.

Step #4 – Figure Out Which Is The Right Toilet Flapper Fit

The rule: “One size doesn’t fill all” is valid for toilet flappers. And most – but not all – US flappers will take a standard 2- or 3-inch diameter.

The analogy with orange or grapefruit can help you figure out whether you need a smaller or larger size. But the perfectionists will determine the right flapper size when they measure the inner diameter of the small circular shape.

Another trick is to look for the toilet model number inside of the toilet tank or on the cistern lid. The serial number will help you find the right fit by looking at the toilet manufacturer’s instructions.

Step #5 – Exchange The Faulty Flapper With An Exact-match Part

When it comes to flapper fitting, this is just a reverse of the removal steps above. Let the new flapper sit into place and gently connect the hooks to the pins on the overflow pipe. Next, reattach the chain to the lever and ensure a slack of ¼ to ½ inches so that the flapper can create a good seal and lift all the way.

Step #6 – Do A Final Test

Once you restore the assembly, turn the water back on. With an open lid, flush the toilet and check if the parts work in tandem.

Voila! You can now enjoy the sound of a silent toilet.

(Video) How To Fix Running Toilet When New Flapper Still Lets Water Leak Through #Flashlight Video Series

How To Prevent A Leaking Toilet Flapper?

To prevent your toilet flapper from causing you plumbing headaches, and to keep your toilet running smoothly, what are the options?

  • DO NOT use chemical disinfectants or in-tank tablets in your toilet tank. They can eat up the flapper and cause it to fail;
  • DO clean your toilet tank with a mild natural cleaner at least once a year.
  • DO make a visual inspection of your toilet’s inner parts at least twice a year.

These steps will save you a mess with your household plumbing and help you save on your water bills. Plus, if you pay enough attention to in-tank maintenance, you may prolong the life of your flapper valve.

Is Your Toilet Flapper Still Leaking After Replacement?

Toilet flapper leak repairs can be easily DIY-ed, but can become a tradesperson’s job if the changed component still runs. In 99% of the instances, the problem roots in an ill-fitting technique, ignoring the cleaning step, the chain doesn’t fit properly with the flapper, or worn-out bottom-tank rubber washers, letting the water through.

Your best option? Buy yourself peace of mind when you contact the Twin Home Experts today. We have local experts that are able to repair any toilet running situation the same day in less than an hour.

Special Guest Writer & Author Bio

(Video) STILL LEAKING? HERE'S HOW TO FIX IT! American Standard Champion Four Toilet

Harry H. Knowles is a certified plumbing professional at the London-based My Plumber company. Established in 2005, My Plumber is now an award-winning company, part of Fantastic Services, and offers a diverse range of general plumbing installations and repairs, as well as gas heating services, including the installation of boilers and central heating systems.


How do I stop my toilet flapper from leaking? ›

What should you do if your toilet flapper is leaking?
  1. Turn off the water supply to the toilet.
  2. Drain the tank.
  3. Unhook the chain from the tank.
  4. Disconnect the old flapper.
  5. Clean up the seal under the flapper.
  6. Install the new flapper and reattach the chain.

How do I know if my flush valve or flapper is leaking? ›

And if you come back if you notice that your water level has dropped a little bit. Well. That's a

Why is my new flapper still leaking? ›

Replace the Flapper

If you've tried replacing the toilet flapper but the toilet still runs, the flush valve seat is probably rough or pitted. You can replace the entire flush toilet flapper valve, but it's a big job.

Will Vaseline help seal toilet flapper? ›

One easy, but temporary fix to make rubber toilet parts supple again is vaseline. The toilet must be drained and dried for this to work. Then, vaseline can be rubbed on the flapper and it's connecting washer until they become soft. The toilet should be filled and checked again.

How do you fix a flapper seal? ›

How to Fix a Toilet - Flapper Valve Replacement - YouTube

Why is my toilet still running after replacing flush valve? ›

Attach the new valve and adjust the float to the desired water level. If your toilet is still running constantly after replacing bad parts or making adjustments, the problem may not be water pressure. A clogged toilet could be the culprit.

How can you tell if your toilet flapper is bad? ›

The tell-tale signs that you might have a malfunctioning flapper are:
  1. Toilet water runs intermittently or for a longer amount of time than usual;
  2. Rippling water move in the bowl between flushes;
  3. Low flushing power and hissing “filling” sounds;
  4. Jiggling the toilet handle doesn't stop the toilet from flushing;

How often should toilet flapper be replaced? ›

The average toilet flapper lasts about 4 to 5 years. It is important that you replace your toilet flapper when needed to prevent damaging leaks.

How do you adjust a flapper? ›

How to Adjust Toilet Flapper Float that Closes Too Soon or Too Fast

How do I add weight to my toilet flapper? ›

Add weight to the flapper: find a half-inch nut, remove the chain from the lever, put the chain up through the nut and re-attach it to the lever. The chain will keep the nut from getting in the way of closure. Hello, and welcome to Home Improvement.

Why does my flush valve leak? ›

If the flapper is worn or the seat that the flapper rests on is damaged, the water level will stop just below the flapper. If the gasket that seals the flush valve into the tank is deteriorated and leaking, the water would most likely drain completely out of the tank.

Can toilet flapper be cleaned? ›

Clean the Flapper

Don a pair of rubber gloves. Gently lift the flapper and scrub it with an old toothbrush or scouring pad. Scrub the seat assembly as well. Turn the water back on and test your work.

Will Vaseline stop a water leak? ›

Using Vaseline to Stop a Leak

Wipe up any water left inside the tank with a sponge. Lift the flapper and prop it against the overflow tube. Apply a light coat of Vaseline around the rim of the flush valve opening. Lower the flapper and restore the water supply by opening the supply valve.

Is Vaseline a sealant? ›

Petroleum jelly is also a great sealant. If you fear that your plunger isn't working in the bathroom and you need to get a better seal - use Vaseline! Cover the plunger's rim with jelly and you'll be able to get a better seal and better suction.

Are all toilet flappers the same size? ›

Flappers comes in two sizes, two inch and three inch. A majority of toilets will use the two inch flapper; however three inch flappers have become popular in recent years and can be found in newer toilets manufactured since 2005.

Why does my toilet randomly run for a few seconds? ›

If a toilet randomly runs for a few seconds and empties without flushing, it's likely the result of a cracked toilet flapper, the chain being caught, the float needing to be lowered, or the refilling tube needing to be repositioned.

How do I stop my toilet from running periodically? ›

You Need to Lower the Float

Among the most common causes for a running toilet is overflow water leaking down into the bowl from the tank via the overflow tube. This happens when there's too much water in the tank. You can adjust the water level by adjusting the height of the float.

Why is my toilet still leaking? ›

Check the Connections between the Toilet Bowl & Tank

Begin by tightening the bolt nuts underneath the tank with an adjustable wrench. If the nuts keep spinning, try tightening them from the inside of the tank. If all connections feel tight but the tank still leaks, replace the washers to restore a water-tight seal.

How much does it cost to fix a toilet flapper? ›

If you need a flapper replaced, prices range from $60 to $120. The flapper is a rubber component that sits against the flush valve opening. In some older models, the tank ball does the work of the flapper.

How do I know where my toilet is leaking from? ›

How to Find a Toilet Leak - YouTube

Are toilet flappers universal? ›

Are all toilet flappers universal? No. There are universal designs like the Fluidmaster flappers that replace most other flappers and there are specialty flappers for specific flushing systems.

Can I replace toilet flapper myself? ›

However, the tradeoff is they corrode over time and will generally need to be replaced about every two years or so. There's more good news: you can replace a toilet flapper yourself! They cost just a few dollars at your local hardware store, and require no specialized tools or training to replace it.

Is changing a toilet flapper easy? ›

Plumbing Tips - How to Replace a Toilet Flapper Valve | Roto-Rooter

How do I know if I need a new flush valve? ›

How to Know When Your Fill Valve on a Toilet Needs Replacing - YouTube

How do you adjust a flush valve? ›

FluidMaster® Fill Valve : Adjusting Your Water Level - YouTube

How do you replace the fill valve on a toilet flapper? ›

How to Replace a Toilet Fill Valve - The Home Depot - YouTube

How do I adjust the float in my toilet? ›

How to Adjust a Toilet Float - YouTube

How long should toilet flapper stays open? ›

The bottom line is that the flapper has to stay open long enough for the toilet to flush completely. If you have a contemporary low-flow toilet, the flapper can rise almost to the vertical position; it will then stay open long enough for the level of the water in the tank to fall to the rim of the siphon tube.

How do you adjust toilet so you don't have to hold the handle down? ›

To fix this issue, you just have to know how to adjust toilet flapper. To do this, adjust the chain length so there is only about ½ inch of slack. Trim the length of the leftover chain if it hangs down too far and interferes with any part.

Why is my toilet still running after replacing flush valve? ›

Attach the new valve and adjust the float to the desired water level. If your toilet is still running constantly after replacing bad parts or making adjustments, the problem may not be water pressure. A clogged toilet could be the culprit.

How much water can a leaky flapper waste? ›

How much water does a bad flapper waste? Depending on the extent of the leak, a warped or poorly fitting flapper can waste up to 200 gallons of water a day and may cost you hundreds of dollars a year.

Why is my toilet flush valve leaking? ›

The most common cause of a leaking toilet tank is when the flapper fails to seat properly and form a tight seal against the valve seat. This lets water leak from the tank into the bowl. It may be caused by the flapper being out of position.

How do I stop my toilet water from running? ›

How To Stop a running TOILET in SECONDS - YouTube

Why does my toilet randomly run for a few seconds? ›

If a toilet randomly runs for a few seconds and empties without flushing, it's likely the result of a cracked toilet flapper, the chain being caught, the float needing to be lowered, or the refilling tube needing to be repositioned.

Is it bad if my toilet keeps running? ›

A constantly running toilet is typically due to an issue with the flush valve assembly, so one of the first parts to inspect should be the chain and flapper. If the chain is too short, then it won't allow the flapper to close properly, but if it is too long it may get trapped underneath the flapper, causing it to leak.

How much does it cost to fix a leaky toilet? ›

The national average materials cost to repair a leaky toilet is $18.55 per toilet, with a range between $17.36 to $19.75. The total price for labor and materials per toilet is $223.63, coming in between $202.77 to $244.49.

How do you clean a toilet flapper? ›

Clean the Flapper

Flush the toilet to empty the tank. Don a pair of rubber gloves. Gently lift the flapper and scrub it with an old toothbrush or scouring pad. Scrub the seat assembly as well.

How much can a toilet leak per day? ›

The average leaky toilet can waste about 200 gallons of water per day. That's over 6,000 gallons a month ($70.06*) for just one leaking toilet!

How do I stop my toilet running every few minutes? ›

This problem is almost certainly caused by a bad flapper or flapper seat. The solution is to drain the tank and bowl, check and clean the flapper seat and then replace the flapper if it's worn or damaged.


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